#include <iostream>
#include <cstdint>
#include <vector>

using namespace std;

int main() {

  ios::sync_with_stdio(false);
  cin.tie(0);

  int64_t n;
  cin >> n;
  vector<int64_t> v(n);
  for (auto& i : v) {
    cin >> i;
  }
  cout << v.at(n - 1) << "/" << v.at(0) << endl;
  return 0;
}