为啥洛谷编译失败？dev上样例过了

#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=1e3+5;
int p[N*2];
find(int x){
	if(x==p[x])	return p[x];
	else	return p[x]=find(p[x]);
}
signed main(){
	int n,m;	cin >>n>>m;
	for(int i=1;i<=2*n;i++)	p[i]=i;
	while(m--){
		char a;		cin >>a;
		int x,y;	cin >>x>>y;
		if(a=='F')	p[find(x)]=find(y);
		else{
			p[find(x+n)]=find(y);
			p[find(y+n)]=find(x);
		}
	}
	int ans=0;
	for(int i=1;i<=n;i++){
		if(p[i]==i)	ans++;
	}
	cout <<ans;
	return 0;
}