#include <bits/stdc++.h>
using namespace std;
const long long INF = 1e9 + 10, MAX = 2e5 + 1e4, MOD = 1e9 + 7, MAXL = 25;
void OUT(long double o, int x) {
  cout << fixed << setprecision(x) << o;
  return;
}
long long a[MAX];
long long f(long long x, long long y) {
  if (y == 0) return 1;
  long long z = f(x, y / 2);
  z = (z * z) % MOD;
  if (y % 2 == 1) z = (z * x) % MOD;
  return z;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long n, z = 0, x = 1;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    if (a[i] % 2 == 0) z = 1;
    x = (x * (a[i] % (MOD - 1))) % (MOD - 1);
  }
  long long s1 = 0, s2 = 0;
  if (z == 1)
    s1 = (f(2, x)) + 2;
  else
    s1 = (f(2, x) + MOD - 2) % MOD;
  s2 = (s1 * f(3, MOD - 2)) % MOD;
  cout << (s2 * f(2, MOD - 2)) % MOD;
  cout << "/" << f(2, (x - 1 + MOD - 1));
  return 0;
}
