WHY MLE?

#include<cstdio>
#include<iostream>
using namespace std;
int n,m,fa[10001],z,x,y;
int zhao(int x)
{
    if(x!=fa[x]) fa[x]=zhao(fa[x]);
    return fa[x];
}
void unionn(int a,int b)
{
    b=fa[b];a=fa[a];fa[b]=a;
}
int main()
{
    ios::sync_with_stdio(false);
    cin>>n>>m;
    for(int i=1;i<=n;i++)
        fa[i]=i;
    for(int i=1;i<=m;i++)
    {
        cin>>z>>x>>y;
        if(z==1) unionn(x,y);
        if(z==2)
        {
            if(zhao(x)==zhao(y)) cout<<"Y"<<endl;
            else cout<<"N"<<endl;
        }
    }    
    return 0;
}