简单

已AC！

#include <bits/stdc++.h>
using namespace std;
bool prime(int e)
{
    if (e == 1) return false;
    if (e == 2 || e == 3) return true;
    if (e % 6 != 5 && e % 6 != 1) return false;
    for (int i = 2;i * i <= e;i++)
    {
        if (e % i == 0) return false;
    }
    return true;
}
char a[26];
int main()
{
    string s;
    cin >> s;
    for (int i = 0;i < s.length();i++)
    {
        int u = s[i] - 'a';
        a[u]++;
    }
    sort(a,a + 26);
    int i = 0;
    while (!a[i])
    {
        i++;
    }
    if (prime(a[25] - a[i]))
    {
        cout << "Lucky Word" << endl << a[25] - a[i];
    }
    else
    {
        cout << "No Answer" << endl << 0;
    }
}