急急急急急急！为什么是96.67呢

为什么第二道题差一点呀，求大佬指导指导

这是代码

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<map>

using namespace std;
map<char , int> mp;
int main(){
	int m, n, sum = 1;
	cin >> n >> m;
	string s1 = "meituan";
	for(int i = 0; i < s1.size();i++){
		mp[s1[i]] = 0;
	}
	for(int i = 0; i < n; i++){
		string s;
		cin >> s;
		for(auto x = mp.begin(); x != mp.end();x++){
			if(s.find(x->first) != -1){
				x->second++;
			}
//			cout << x->first  << x->second <<" " ;
		}
//		cout << "\n";
		
	}
	
	for(auto t = mp.begin(); t != mp.end();t++){
		if(t->second == 0){
			sum = 0;
		}
	}
	if(sum && n >= 7){
		cout << "YES";
	}else{
		cout << "NO";
	}
	return 0;
}