#include <bits/stdc++.h>
using namespace std;
int k, p, q, n;
long long x;
const int MO = 1e9 + 7;
int pw(int x, int y) {
  int t = 1;
  for (; y; y >>= 1) {
    if (y & 1) t = (long long)t * x % MO;
    x = (long long)x * x % MO;
  }
  return t;
}
int main() {
  scanf("%d", &k);
  n = 1;
  for (int i = 1; i <= k; i++)
    scanf("%I64d", &x), n = (long long)n * (x % (MO - 1)) % (MO - 1);
  if (n & 1)
    p = (long long)(pw(2, (n + MO - 2) % (MO - 1)) + MO - 1) % MO *
        pw(3, MO - 2) % MO;
  else
    p = (long long)(pw(2, (n + MO - 2) % (MO - 1)) + 1) % MO * pw(3, MO - 2) %
        MO;
  q = pw(2, (n + MO - 2) % (MO - 1));
  if (p == 0) q = 1;
  cout << p << '/' << q << endl;
  return 0;
}
