/*
                FORHAD-SUST-BD
*/
#include <iostream>
#include <string>
#include <map>
#include <queue>
#include <stack>
#include <algorithm>
#include <list>
#include <set>
#include <cmath>
#include <cstring>
#include <stdio.h>
#include <string.h>
#include <sstream>
#include <stdlib.h>
#include <vector>
#include <iomanip>
 
using namespace std;
 
#ifdef __GNUC__
typedef long long ll;typedef unsigned long long ull;
#else
typedef __int64 ll;  typedef unsigned __int64 ull;
#endif
 
#define INF 1<<28
#define SIZE 100
#define PI 2*acos(0)
#define fg %I64d
#define REP(i,n) for (i=0;i<n;i++)
#define REV(i,n) for (i=n;i>=0;i--)
#define FOR(i,p,k) for (i=p; i<k;i++)
#define FOREACH(it,x) for(__typeof((x).begin()) it=(x.begin()); it!=(x).end(); ++it)
 
#define bug(x)    cout<< "->" <<#x<<": "<<x<<endl
#define Sort(x) sort(x.begin(),x.end())
#define Reverse(x) reverse(x.begin(),x.end())
#define MP(a,b) make_pair(a,b)
#define Clear(x,with) memset(x,with,sizeof(x))
#define Copy(c,r)   memcpy(c,r,sizeof(r))
#define SZ(x) (int)x.size()
#define length(x) (int)x.length()
#define All(x) x.begin(),x.end()
#define pb push_back
#define popcount(i) __builtin_popcount(i)
#define gcd(a,b)    __gcd(a,b)
#define fs first
#define sc second
#define two(X) (1<<(X))
#define twoL(X) (((int64)(1))<<(X))
#define contain(S,X) (((S)&two(X))!=0)
#define containL(S,X) (((S)&twoL(X))!=0)
 
typedef pair<int,int> pii;
typedef pair<double,double> pdd;
typedef vector<int> vi;
typedef vector<double>vd;
typedef vector<ll>vll;
typedef vector<string> vs;
typedef vector<vi>vvi;
typedef vector<vll>vvll;
typedef vector<vd>vvd;
typedef vector<pii>vpii;
typedef map<string,int> msi;
typedef map<int,int>mii;
typedef map<pii,int>mpi;
 
template<class T> inline T sqr(T x){return x*x;}
template<class T> inline bool isPrime(T n){if(n<=1)return false;for (T i=2;i*i<=n;i++) if (n%i==0) return false;return true;}
template<class T> inline T Mod(T n,T m) {return (n%m+m)%m;} //For Positive Negative No.
template<class T> string toString(T n){ostringstream oss;oss<<n;oss.flush();return oss.str();}
int toInt(string s){int r=0;istringstream sin(s);sin>>r;return r;}
ll toLl(string s){ll r=0;istringstream sin(s); sin>>r; return r;}
template<class T> void debug(const T& e){cout<<e<<endl;}
template<class T1,class T2> void debug(const T1& e1,const T2& e2){cout<<e1<<"\t"<<e2<<endl;}
template<class T1,class T2,class T3> void debug(const T1& e1,const T2& e2,const T3& e3){cout<<e1<<"\t"<<e2<<"\t"<<e3<<endl;}
template<class T1,class T2,class T3,class T4> void debug(const T1& e1,const T2& e2,const T3& e3,const T4& e4){cout<<e1<<"\t"<<e2<<"\t"<<e3<<"\t"<<e4<<endl;}
template<class T1,class T2,class T3,class T4,class T5> void debug(const T1& e1,const T2& e2,const T3& e3,const T4& e4,const T5& e5){cout<<e1<<"\t"<<e2<<"\t"<<e3<<"\t"<<e4<<"\t"<<e5<<endl;}
template<class T> void debug(vector<T>& e){int i;REP(i,SZ(e)) cout<<e[i]<<" ";cout<<endl;}
template<class T> void debug(vector< basic_string<T> >& e){int i,j;REP(i,SZ(e)) {REP(j,SZ(e[i])) cout<<e[i][j];cout<<endl;} cout<<endl;}
template<class T> void debug(vector< vector<T> >& e){int i,j;REP(i,SZ(e)) {REP(j,SZ(e[i])) cout<<e[i][j]<<"\t";cout<<endl;} cout<<endl;}
template<class T> void debug(T e[SIZE][SIZE],int row,int col){int i,j;REP(i,row) {REP(j,col) cout<<e[i][j]<<" ";cout<<endl;}}
 
ll Pow(ll B,ll P){	ll R=1;	while(P>0)	{if(P%2==1)	R=(R*B);P/=2;B=(B*B);}return R;} //compute b^p
//struct pq{    int cost,node;bool operator<(const pq &b)const{return cost>b.cost;}};// Min Priority Queue
//bool comp(pq a,pq b){    return a.cost > b.cost;}   //Comp Sort
 
//int dx[]={1,0,-1,0};int dy[]={0,1,0,-1}; //4 Direction
//int dx[]={1,1,0,-1,-1,-1,0,1};int dy[]={0,1,1,1,0,-1,-1,-1};//8 direction
//int dx[]={2,1,-1,-2,-2,-1,1,2};int dy[]={1,2,2,1,-1,-2,-2,-1};//Knight Direction
 
int mat[SIZE][SIZE],Color[SIZE],Nodes,check;
 
void dfs(int u)
{
    int i;
 
    REP(i,Nodes)
    {
        if(mat[u][i])
        {
            if(Color[i]==0)
            {
                Color[i]=Color[u]*(-1);
                dfs(i);
            }
            else if(Color[i]==Color[u])
                check=0;
        }
    }
}
 
class Marketing
{
public:
	long long howMany(vector <string> compete)
	{
        ll i,sum=1,u,v;
 
        Nodes=SZ(compete);
        Clear(mat,0);
        REP(i,Nodes)
        {
            istringstream iss(compete[i]);
            u=i;
            while(iss>>v)
            {
                mat[u][v]=mat[v][u]=1;
            }
        }
        Clear(Color,0);
        REP(i,Nodes)
        {
            if(Color[i]==0)
            {
                check=1;
                Color[i]=1;
                dfs(i);
                if(check)
                    sum*=2;
                else return -1;
            }
        }
        return sum;
	}
};
 
 
template<typename T> void print( T a ) {
    cerr << a;
}
 
void print( long long a ) {
    cerr << a << "L";
}
 
void print( string a ) {
    cerr << '"' << a << '"';
}
 
template<typename T> void print( vector<T> a ) {
    cerr << "{";
    for ( int i = 0 ; i != a.size() ; i++ ) {
        if ( i != 0 ) cerr << ", ";
        print( a[i] );
    }
    cerr << "}" << endl;
}
 
template<typename T> void assert_eq( int n, T have, T need ) {
    if ( have == need ) {
        cerr << "Case " << n << " passed." << endl;
    } else {
        cerr << "Case " << n << " failed: expected ";
        print( need );
        cerr << " received ";
        print( have );
        cerr << "." << endl;
    }
}
 
template<typename T> void assert_eq( int n, vector<T> have, vector<T> need ) {
    if( have.size() != need.size() ) {
        cerr << "Case " << n << " failed: returned " << have.size() << " elements; expected " << need.size() << " elements.";
        print( have );
        print( need );
        return;
    }
    for( int i= 0; i < have.size(); i++ ) {
        if( have[i] != need[i] ) {
            cerr << "Case " << n << " failed. Expected and returned array differ in position " << i << ".";
            print( have );
            print( need );
            return;
        }
    }
    cerr << "Case " << n << " passed." << endl;
}
void assert_eq( int n, string have, string need ) {
    if ( have == need ) {
        cerr << "Case " << n << " passed." << endl;
    } else {
        cerr << "Case " << n << " failed: expected ";
        print( need );
        cerr << " received ";
        print( have );
        cerr << "." << endl;
    }
}
 
int main( int argc, char* argv[] )
{
 
	Marketing objectMarketing;
 
	//test case0
	vector <string> param00;
	param00.push_back("1 4");
	param00.push_back("2");
	param00.push_back("3");
	param00.push_back("0");
	param00.push_back("");
	long long ret0 = objectMarketing.howMany(param00);
	long long need0 = 2;
	assert_eq(0,ret0,need0);
 
	//test case1
	vector <string> param10;
	param10.push_back("1");
	param10.push_back("2");
	param10.push_back("0");
	long long ret1 = objectMarketing.howMany(param10);
	long long need1 = -1;
	assert_eq(1,ret1,need1);
 
	//test case2
	vector <string> param20;
	param20.push_back("1");
	param20.push_back("2");
	param20.push_back("3");
	param20.push_back("0");
	param20.push_back("0 5");
	param20.push_back("1");
	long long ret2 = objectMarketing.howMany(param20);
	long long need2 = 2;
	assert_eq(2,ret2,need2);
 
	//test case3
	vector <string> param30;
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	param30.push_back("");
	long long ret3 = objectMarketing.howMany(param30);
	long long need3 = 1073741824;
	assert_eq(3,ret3,need3);
 
	//test case4
	vector <string> param40;
	param40.push_back("1");
	param40.push_back("2");
	param40.push_back("3");
	param40.push_back("0");
	param40.push_back("5");
	param40.push_back("6");
	param40.push_back("4");
	long long ret4 = objectMarketing.howMany(param40);
	long long need4 = -1;
	assert_eq(4,ret4,need4);
 
}