#include<cstdio>

 #include<cstdlib>

 #include<algorithm>

 #include<cstring>

 #define MAXN 35

 using namespace std;

 int a[MAXN][MAXN];

 int gauss(int m,int n){

     int ret=,line=;

     for(int k=;k<=m;k++){

         int i=line;

         while(i<=m){if(a[i][k])break;i++;}

         if(i>m){ret++;continue;}//自由元

         if(i!=line){for(int j=k;j<=n;j++)swap(a[i][j],a[line][j]);}

         for(i=line+;i<=m;i++){

             if(a[i][k]){

                 for(int j=k;j<=n;j++){

                     a[i][j]^=a[line][j];

                 }

             }

         }

         line++;

     }

     for(int i=line;i<=m;i++)if(a[i][n])return -;

     //最后一定都消成0了,所以a[i][n]必须为0才符合题意

     return ret;

 }

 int n;

 void solve(){

     memset(a,,sizeof(a));

     scanf("%d",&n);

     for(int i=;i<=n;i++)scanf("%d",&a[i][n+]);

     int x,y;

     for(int i=;i<=n;i++){scanf("%d",&x);a[i][n+]^=x;}

     for(int i=;i<=n;i++){a[i][i]=;}

     while(){

         scanf("%d%d",&x,&y);

         if(!x&&!y)break;

         a[y][x]=;

     }

     int ans=gauss(n,n+);

     if(-==ans)printf("Oh,it's impossible~!!\n");

     else printf("%d\n",<<ans);

 }

 int main()

 {

 //    freopen("data.in","r",stdin);

     int T;

     scanf("%d",&T);

     while(T--){

         solve();

     }

     return ;

 }