#include <bits/stdc++.h>
using namespace std;
long long int powmod(long long int a, long long int b) {
  if (b == 0) return 1;
  long long int x = powmod(a, b / 2);
  long long int y = (x * x) % 1000000007;
  if (b % 2) return (a * y) % 1000000007;
  return y % 1000000007;
}
long long int a[100010];
int main() {
  long long int n;
  scanf("%lld", &n);
  bool even = false;
  long long int p = 1;
  long long int den = 2LL;
  long long int num = 2LL;
  for (int i = 0; i < n; i++) {
    scanf("%lld", &a[i]);
    if (a[i] % 2 == 0) even = true;
    if (p == 1) p *= a[i];
    den = powmod(den, a[i]);
    num = powmod(num, a[i]);
  }
  den *= powmod(2LL, 1000000007 - 2);
  den %= 1000000007;
  num *= powmod(2LL, 1000000007 - 2);
  num %= 1000000007;
  if (p == 1) {
    printf("0/1\n");
    return 0;
  }
  if (even) {
    num += 1LL;
    num %= 1000000007;
    num *= powmod(3, 1000000007 - 2);
    num %= 1000000007;
    printf("%lld/%lld\n", num, den);
  } else {
    num += 1000000007 - 1;
    num %= 1000000007;
    num *= powmod(3, 1000000007 - 2);
    num %= 1000000007;
    printf("%lld/%lld\n", num, den);
  }
  return 0;
}
