UVA 3644 X-Plosives

#include<bits/stdc++.h>
using namespace std;
int fat[100010];
int find(int x){
	if(fat[x]==0)return x;
	return fat[x]=find(fat[x]);
}
int main(){
	int x,y,q,p,ans;
	while(scanf("%d",&x)!=EOF){	
		ans=0;
		memset(fat,0,sizeof(fat));
		do{
			scanf("%d",&y);
			q=find(x);
			p=find(y);
			if(q==p)ans++;
			else fat[q]=p;
		}while(scanf("%d",&x)&&x!=-1);
		printf("%d\n",ans);
	}
	return 0;
}