#include <bits/stdc++.h>
using namespace std;
long long mod = 1e9 + 7;
long long ksm(long long a, long long b) {
  long long c = 1;
  while (b) {
    if (b % 2) c = c * a % mod;
    a = a * a % mod;
    b = b / 2;
  }
  return c;
}
int K;
long long A[101010];
int main() {
  scanf("%d", &K);
  int flag = false;
  for (int i = 1; i <= K; i++) {
    scanf("%I64d", &A[i]);
    if (A[i] % 2 == 0) flag = true;
  }
  long long p = 1, q = 1;
  if (!flag) {
    for (int i = 1; i <= K; i++) {
      q = A[i] % (mod - 1) * q % (mod - 1);
    }
    q = (q - 1 + mod - 1) % (mod - 1);
    q = ksm(2, q);
    p = (q - 1) * ksm(3, mod - 2) % mod;
  } else {
    for (int i = 1; i <= K; i++) {
      q = A[i] % (mod - 1) * q % (mod - 1);
    }
    q = (q - 1 + mod - 1) % (mod - 1);
    q = ksm(2, q);
    p = (q + 1) * ksm(3, mod - 2) % mod;
  }
  printf("%I64d/%I64d\n", p, q);
  return 0;
}
