Uva-1160-X-Plosives

#include<cstdio>
#include<cstring>
#include<iostream>
#define MAX 100001
using namespace std;
int p[MAX],ans;
int find(int x)
{
if(p[x]==x)
return x;
return p[x]=find(p[x]);
}
int main()
{
int a,b;
while(scanf("%d",&a)!=EOF)
{
for(int i=0;i<MAX;i++)
p[i]=i;
ans=0;
while(1)
{
scanf("%d",&b);
int ita=find(a);
int itb=find(b);
if(ita==itb)
ans++;
else
p[ita]=itb;
scanf("%d",&a);
if(a==-1)
break;
}
printf("%d\n",ans);
}
return 0;
}