#include <bits/stdc++.h>
using namespace std;
long long ha = 1000000000 + 7;
long long n = 1, a[100004], k;
long long pow2(long long a, long long b) {
  long long ans = 1, base = a, h = b;
  base %= ha;
  while (h) {
    if (h & 1) ans = ans * base % ha;
    h >>= 1;
    base = base * base % ha;
  }
  return ans;
}
int main() {
  cin >> k;
  int isodd = 1;
  for (int i = 1; i <= k; i++) {
    scanf("%lld", &a[i]);
    if (a[i] % 2 == 0) isodd = 0;
    n *= a[i] % (ha - 1), n %= (ha - 1);
  }
  n = n % (ha - 1) + ha - 1;
  if (!isodd)
    isodd = 1;
  else
    isodd = -1;
  long long inv3 = pow2(3, ha - 2);
  long long p = (pow2(2, n - 1) + isodd) * inv3 % ha;
  long long q = pow2(2, n - 1);
  cout << p << "/" << q << endl;
}
