#include <bits/stdc++.h>
using namespace std;
long long T[100005];
long long mod = 1000000007;
long long pow(long long a, long long b) {
  long long c = 1;
  while (b) {
    if (b % 2 == 1) c *= a, c %= mod;
    a *= a;
    a %= mod;
    b /= 2;
  }
  return c;
}
int main() {
  ios_base::sync_with_stdio(0);
  int n;
  cin >> n;
  bool two = false;
  for (int i = 0; i < n; i++) {
    cin >> T[i];
    if (T[i] % 2 == 0) two = true;
  }
  long long num = 2;
  for (int i = 0; i < n; i++) {
    num = pow(num, T[i]);
    num %= mod;
  }
  long long denom = num;
  denom *= pow(2, mod - 2);
  denom %= mod;
  if (two)
    num += 2, num %= mod;
  else
    num += mod - 2, num %= mod;
  num *= pow(6, mod - 2);
  num %= mod;
  cout << num << "/" << denom << "\n";
  return 0;
}
