#include <bits/stdc++.h>
using namespace std;
int mod = 1e9 + 7;
int pwr(int b, long long ex) {
  int ret = 1;
  while (ex > 0) {
    if (ex & 1) {
      ret = 1ll * ret * b % mod;
    }
    b = 1ll * b * b % mod;
    ex >>= 1;
  }
  return ret;
}
int main() {
  std::ios_base::sync_with_stdio(false);
  int k;
  cin >> k;
  vector<long long> a(k);
  bool odd = true;
  for (auto &first : (a)) {
    cin >> first;
    odd = odd && first % 2 != 0;
  }
  sort((a).begin(), (a).end());
  if (a[0] == 1 && a.back() == 1) {
    cout << "0/1";
    return 0;
  }
  int tn = 2;
  for (auto first : (a)) {
    tn = pwr(tn, first) % mod;
  }
  int v = 1ll * tn * pwr(2, mod - 2) % mod, u;
  if (odd) {
    u = 1ll * (tn - 2 + mod) % mod * pwr(6, mod - 2) % mod;
  } else {
    u = 1ll * (tn + 2) % mod * pwr(6, mod - 2) % mod;
  }
  cout << u << "/" << v;
  return 0;
}
