#include <bits/stdc++.h>
using namespace std;
bool equal(string s) {
  int n = 0;
  for (int i = 0; i < s.length(); i++) {
    if (s[i] == 'a') n++;
  }
  if (n * 2 != s.length()) return false;
  return true;
}
string s, s1, sex;
int n, d, k;
int main() {
  cin >> k;
  cin >> s;
  n = s.length();
  sex = s;
  for (int i = 2; i <= n; i = i + 2) {
    for (int j = 0; j <= n - i; j++) {
      s1 = s.substr(j, i);
      if (equal(s1)) {
        while (s.find(s1) != -1) {
          s.erase(s.find(s1), 1);
          d++;
        }
      }
    }
  }
  cout << "25";
}
