#include <bits/stdc++.h>
using namespace std;
const int MX = 3e5 + 5;
const int INF = 0x3f3f3f3f;
const int mod = 1e9 + 7;
const double eps = 1e-10;
long long power(long long a, long long b) {
  long long ret = 1;
  while (b) {
    if (b & 1) ret = ret * a % mod;
    a = a * a % mod;
    b >>= 1;
  }
  return ret;
}
int main() {
  int n, cnt = 0;
  long long s = 1;
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    long long t;
    scanf("%I64d", &t);
    if (!(t & 1)) cnt++;
    t %= mod - 1;
    s = s * t % (mod - 1);
  }
  long long s2 = (s - 1 + mod - 1) % (mod - 1);
  long long a = power(2, s2) % mod, b;
  if (!cnt)
    b = (power(2, s2) - 1) * power(3, mod - 2) % mod;
  else
    b = (power(2, s2) + 1) * power(3, mod - 2) % mod;
  printf("%I64d/%I64d\n", b, a);
  return 0;
}
