#include <bits/stdc++.h>
using namespace std;
ifstream in("file.in");
ofstream out("file.out");
const long long mod = 1000000007;
long long k, a[100005];
long long power(long long n, long long p) {
  if (p == 1) return n % mod;
  if (p % 2 == 0) return power(n * n % mod, (p / 2)) % mod;
  if (p % 2 == 1) return n % mod * power(n * n % mod, ((p - 1) / 2)) % mod;
}
int sus() {
  long long ans = 2;
  bool par = 0;
  for (int i = 1; i <= k; i++) {
    ans = power(ans, a[i]);
    if (!(a[i] % 2)) par = 1;
  }
  ans = (ans * power(2, 1000000005)) % mod;
  if (!par)
    ans = (ans - 1);
  else
    ans = (ans + 1) % mod;
  if (ans < 0) ans += mod;
  ans = (ans * power(3, 1000000005)) % mod;
  return ans;
}
long long jos() {
  long long ans = 2;
  for (int i = 1; i <= k; i++) {
    ans = power(ans, a[i]);
  }
  ans = (ans * power(2, 1000000005)) % mod;
  return ans;
}
int main() {
  ios_base ::sync_with_stdio(0);
  cin >> k;
  for (int i = 1; i <= k; i++) cin >> a[i];
  cout << sus() << '/' << jos();
}
