poj2524

#include<stdio.h>
#include<iostream>

using namespace std;

int bin[50010];
int findx(int x)
{
    return x == bin[x]?bin[x]:(bin[x] = findx(bin[x]));
}

int main()

{
    int n,m;
    int cas = 1;
    while(scanf("%d%d",&n,&m)&&m||n)
    {
        for(int i = 1;i <= n;i++)
        {
            bin[i] = i;
        }
        for(int i = 0;i < m;i++)
        {
            int a,b;
            scanf("%d%d",&a,&b);
            int fx,fy;
            fx = findx(a);
            fy = findx(b);
            if(fx != fy)
            {
                bin[fx] = fy;
            }
        }
        int sum = 0;
        for(int i = 1;i <= n;i++)
        {
            if(bin[i] == i)
            {
                sum++;
            }
        }
        printf("Case %d: %d\n",cas++,sum);
    }
    return 0;
}