#include <bits/stdc++.h>
using namespace std;
long long int powmod(long long int base, long long int exponent) {
  if (exponent == 0) return 1;
  long long int temp = powmod(base, exponent / 2);
  temp = temp % 1000000007;
  if (exponent % 2 == 0)
    return (temp * temp) % 1000000007;
  else
    return ((base % 1000000007) * ((temp * temp) % 1000000007)) % 1000000007;
}
long long a[100005];
int main() {
  int n;
  cin >> n;
  long long temp = 1;
  int c = 0;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    if (a[i] % 2 == 0) c = 1;
    a[i] = a[i] % 1000000006;
    temp = (temp * a[i]) % 1000000006;
  }
  long long temp2 =
      (1ll * powmod(2, temp) * powmod(2, 1000000007 - 2)) % 1000000007;
  if (c) {
    cout << (1ll * ((temp2 + 1) % 1000000007) * powmod(3, 1000000007 - 2)) %
                1000000007;
  } else
    cout << (1ll * ((temp2 - 1 + 1000000007) % 1000000007) *
             powmod(3, 1000000007 - 2)) %
                1000000007;
  cout << "/";
  cout << temp2;
  return 0;
}
