#include <bits/stdc++.h>
using namespace std;
const long long K = 100000 + 10, MOD = 1000 * 1000 * 1000 + 7;
long long n = 1, k, x, y, z, num, den, a[K];
bool isEven;
long long power(long long base, long long exp) {
  base %= MOD;
  if (!exp) return 1;
  return (power(base * base, exp / 2) * (exp % 2 ? base : 1)) % MOD;
}
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long i;
  cin >> k;
  for (i = 0; i < k; ++i) {
    cin >> a[i];
    n = (1LL * n * (a[i] % (MOD - 1))) % (MOD - 1);
    if (!(a[i] % 2)) isEven = 1;
  }
  x = (1LL * power(2, n) * power(2, MOD - 2)) % MOD;
  y = power(3, MOD - 2);
  den = x;
  x = (isEven ? (x + 1) % MOD : --x);
  num = (1LL * x * y) % MOD;
  cout << num << '/' << den << '\n';
  return 0;
}
