#include <bits/stdc++.h>
using namespace std;
unsigned long long int tab[100100];
unsigned long long int mod = 1000000007;
unsigned long long int fastPow(unsigned long long int a,
                               unsigned long long int b) {
  unsigned long long int ans = 1;
  while (b) {
    if (b & 1) ans = (1ll * a * ans) % mod;
    a = (1ll * a * a) % mod;
    b /= 2;
  }
  return ans;
}
int main() {
  int n;
  scanf("%d", &n);
  bool pair = false;
  bool notOne = false;
  for (int i = 0; i < n; i++) {
    unsigned long long int a;
    scanf("%lld", &a);
    if (a != 1) notOne = true;
    if (a % 2 == 0) pair = true;
    tab[i] = a;
  }
  unsigned long long int q = 2;
  for (int i = 0; i < n; i++) {
    q = (fastPow(q, tab[i])) % mod;
  }
  q = (q * fastPow(2, mod - 2)) % mod;
  unsigned long long int p;
  if (pair)
    p = ((q + 1) * fastPow(3, mod - 2)) % mod;
  else
    p = ((q - 1) * fastPow(3, mod - 2)) % mod;
  cout << p << "/" << q << endl;
  return 0;
}
