请看代码

#include<bits/stdc++.h>
using namespace std;
int s[100];

bool is_prime(int x){ 
	if(x == 0) return 0;
	if(x == 1) return 1;
	if(x == 2) return 1;
	for(int i = 2; i < x; i++){
		if(x % i == 0){
			return 0;
		}
	}
	return 1;
}

int main(){
	string a;
	cin >> a;
	int len = a.size();
	for(int i = 0; i < len; i++){
		s[a[i]-'a']++;
	}
	int maxn = -1;
	int minn = 500;
	for(int i = 0; i < 26; i++){
		if(s[i] > maxn) maxn = s[i];
		if(s[i] < minn && s[i] != 0) minn = s[i];
	}
	int c = maxn - minn;
	if(is_prime(c)){
		cout << "Lucky Word" << endl << c;
	} 
	else{
		cout << "No Answer" << endl << 0;
	}
	return 0;
}