有没有大佬帮忙看看P1892 90分 WA#7……

#include<bits/stdc++.h>
#define N 1010
#define INF 0x3f3f3f3f
using namespace std;
int n, m, f[N], d[N], ans = 0;
int find(int x) {
	if (f[x] != x) return f[x] = find(f[x]);
	else return f[x];
}
void unions(int x, int y) {
	f[y] = x;
}
int main() {
	scanf("%d %d", &n, &m);
	for (int i = 1; i <= n; i++) f[i] = i;
	for (int i = 1; i <= m; i++) {
		char cp;
		int p, q;
		cin >> cp;
		scanf("%d %d", &p, &q);
		if (cp == 'F') unions(find(p), find(q));
		if (cp == 'E') {
			if (d[p]) unions(find(d[p]), find(q));
			d[p] = q;
		}
	}
	for (int i = 1; i <= n; i++) {
		if (f[i] == i) ans++;
	}
	printf("%d", ans);
	return 0;
}