#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
const int MAX = 100005;
long long a[MAX];
int b_pow(int a, int b) {
  int ans = 1;
  while (b) {
    if (b & 1) ans = 1LL * ans * a % MOD;
    b >>= 1;
    a = 1LL * a * a % MOD;
  }
  return ans;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  bool even = false;
  int mul = 1;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    if (a[i] % 2 == 0) even = true;
    mul = 1LL * mul * (a[i] % (MOD - 1)) % (MOD - 1);
  }
  mul = (mul - 1 + (MOD - 1)) % (MOD - 1);
  int p = b_pow(2, mul);
  int q = p;
  if (even)
    p++;
  else
    p--;
  p = 1LL * p * b_pow(3, MOD - 2) % MOD;
  cout << p << "/" << q << "\n";
  return 0;
}
