zoj 1789 The Suspects

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>

int p[30000+100];
int a[30000+100];

int find(int x)
{
if(p[x] == x)
return x;
p[x] = find(p[x]);
return p[x];
}

int main()
{
int n,m,k,i,count,temp;
while(scanf("%d%d",&n,&m) == 2,n*n+m*m)
{
for(i=0;i<n;i++)
p[i] = i;
while(m--)
{
scanf("%d",&k);
for(i=0;i<k;i++)
scanf("%d",&a[i]);
for(i=0;i<k-1;i++)
if(find(p[a[i]]) != find(p[a[i+1]]))
p[find(p[a[i+1]])] = find(p[a[0]]);
}
count = 0;
for(i=0;i<n;i++)
if(find(i) == find(0))
count++;
printf("%d\n",count);
}
return 0;
}