문제

링크

풀이

#include <iostream>
using namespace std;
 
int gcd(int a, int b) {
  return b ? gcd(b, a % b) : a;
}
 
void solve(void) {
  int m; cin >> m;
 
  int a = m * m * (90 - m);
  int b = 108000;
  int g = gcd(a, b);
  cout << a / g << "/" << b / g;
}
 
int main(void) {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
 
  solve();
  return 0;
}