#include <bits/stdc++.h>
void quit();
using namespace std;
const long double PI = acos(-1);
const long double EPS = 1e-10;
double __t;
int n;
long long a[100500];
const long long M = 1000000007;
inline long long powMod(long long b, long long e) {
  long long res = 1;
  while (e) {
    if (e & 1) {
      res = (res * b) % M;
    }
    b = (b * b) % M;
    e >>= 1;
  }
  return res;
}
inline long long inv(long long a) { return powMod(a, M - 2); }
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> n;
  bool hasEven = 0;
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
    if (a[i] % 2 == 0) {
      hasEven = 1;
    }
  }
  long long p = 2;
  for (int i = 0; i < n; ++i) {
    p = powMod(p, a[i]);
  }
  p = (p * inv(2)) % M;
  long long q = p;
  if (hasEven) {
    p = (p + 1) % M;
    p *= inv(3);
    p %= M;
    cout << p << '/' << q;
  } else {
    p = (p - 1 + M) % M;
    p *= inv(3);
    p %= M;
    cout << p << '/' << q;
  }
  quit();
}
void quit() { exit(0); }
