#include <bits/stdc++.h>
using namespace std;
template <typename T>
T gcd(T a, T b) {
  if (a == 0) return b;
  return gcd(b % a, a);
}
template <typename T>
T pow(T a, T b, long long m) {
  T ans = 1;
  while (b > 0) {
    if (b % 2 == 1) ans = ((ans % m) * (a % m)) % m;
    b /= 2;
    a = ((a % m) * (a % m)) % m;
  }
  return ans % m;
}
const long double eps = 1e-10L;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  long long n;
  cin >> n;
  long long p = 1;
  long long a[n + 1];
  long long f = 0;
  for (long long i = 1; i <= n; i++) {
    cin >> a[i];
    p *= (a[i] % ((long long)(1000 * 1000 * 1000 + 7) - 1));
    p %= ((long long)(1000 * 1000 * 1000 + 7) - 1);
    if (a[i] % 2 == 0) f = 1;
  }
  p--;
  p += ((long long)(1000 * 1000 * 1000 + 7) - 1);
  p %= ((long long)(1000 * 1000 * 1000 + 7) - 1);
  if (f) {
    long long nemo1 = pow(2LL, p, (long long)(1000 * 1000 * 1000 + 7));
    nemo1 += 1;
    nemo1 %= (long long)(1000 * 1000 * 1000 + 7);
    nemo1 *= pow(3LL, (long long)(1000 * 1000 * 1000 + 7) - 2,
                 (long long)(1000 * 1000 * 1000 + 7));
    nemo1 %= (long long)(1000 * 1000 * 1000 + 7);
    long long deno1 = pow(2LL, p, (long long)(1000 * 1000 * 1000 + 7));
    deno1 %= (long long)(1000 * 1000 * 1000 + 7);
    cout << nemo1 << "/" << deno1;
  } else {
    long long nemo1 = pow(2LL, p, (long long)(1000 * 1000 * 1000 + 7));
    nemo1 -= 1;
    nemo1 += (long long)(1000 * 1000 * 1000 + 7);
    nemo1 %= (long long)(1000 * 1000 * 1000 + 7);
    nemo1 *= pow(3LL, (long long)(1000 * 1000 * 1000 + 7) - 2,
                 (long long)(1000 * 1000 * 1000 + 7));
    nemo1 %= (long long)(1000 * 1000 * 1000 + 7);
    long long deno1 = pow(2LL, p, (long long)(1000 * 1000 * 1000 + 7));
    deno1 %= (long long)(1000 * 1000 * 1000 + 7);
    cout << nemo1 << "/" << deno1;
  }
}
