poj 1161 The Suspects

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <algorithm>
#include <set>
#include <map>
#include <vector>

using namespace std;

int n,m,k,a,b,pre[100005];

int Find(int x){
if(x == pre[x]) return x;
return pre[x] = Find(pre[x]);
}

void join(int x,int y){
int p = Find(x);
int q = Find(y);
if(p != q) pre[q] = p;
}

int main(){
while(~scanf("%d%d",&n,&m)&&n+m){
for(int i = 0;i < n;i++)
pre[i] = i;
while(m--){
scanf("%d",&k);
scanf("%d",&a);
for(int i = 1;i < k;i++)
scanf("%d",&b),join(a,b);
}
int ans = 0;
for(int i = 0;i < n;i++){
if(Find(i) == Find(0))
ans++;
}
printf("%d\n",ans);
}
return 0;
}