#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007LL;
long long pow_mod(long long a, long long p) {
  long long ret = 1;
  for (; p; p >>= 1, a = a * a % mod)
    if (p & 1) ret = ret * a % mod;
  return ret % mod;
}
int main() {
  int n;
  scanf("%d", &n);
  bool even = false;
  long long p = 1;
  for (int i = 0; i < n; ++i) {
    long long x;
    scanf("%lld", &x);
    if (x % 2 == 0) even = true;
    p = p * (x % (mod - 1)) % (mod - 1);
  }
  p--;
  if (p < 0) p += (mod - 1);
  even = !even;
  long long a2 = pow_mod(2, p);
  long long a1 = pow_mod(2, p);
  a1 += even ? -1 : 1;
  a1 = a1 * pow_mod(3, mod - 2) % mod;
  printf("%lld/%lld\n", a1, a2);
  return 0;
}
