学步园

#include <cstdio>
#include <iostream>
#include <cstring>
using namespace std;

const int maxn = 16;

int n,d[1<<maxn],cover[1<<maxn],ALL,a[maxn*2];
int main()
{
  int kase=1;
  while(scanf("%d",&n)==1&&n){
     int ALL = (1<<n) - 1;
     for(int i=0;i<n;i++){
         int m,x; a[i]=(1<<i);
         scanf("%d",&m);
         for(int j=1;j<=m;j++){
            scanf("%d",&x);
            a[i]|=(1<<(x));
         }
     }
     for(int i=1;i<=ALL;i++){
          cover[i]=0;
          for(int j=0;j<n;j++) if(((i>>j)&1)){
            cover[i]|=a[j];
          }
     }
     for(int i=1;i<=ALL;i++){
        d[i]=0;
        for(int s=i;s;s=(s-1)&i) if(cover[s]==ALL)
            d[i]=max(d[i],d[i^s]+1);
     }
     printf("Case %d: %d\n",kase++,d[ALL]);
  }
  return 0;
}