#include <bits/stdc++.h>
using namespace std;
const long double PI = 3.1415926535897932384626433832795;
template <typename S, typename T>
ostream& operator<<(ostream& out, pair<S, T> const& p) {
  out << '(' << p.first << ", " << p.second << ')';
  return out;
}
template <typename T>
ostream& operator<<(ostream& out, vector<T> const& v) {
  int l = v.size();
  for (int i = 0; i < l - 1; i++) out << v[i] << ' ';
  if (l > 0) out << v[l - 1];
  return out;
}
void tr() { cout << endl; }
template <typename S, typename... Strings>
void tr(S x, const Strings&... rest) {
  cout << x << ' ';
  tr(rest...);
}
const int N = 100100;
const long long MOD = 1e9 + 7;
int k;
long long a[N];
long long fast(long long a, long long b) {
  long long ret = 1;
  while (b) {
    if ((b & 1)) ret = (ret * a) % MOD;
    a = (a * a) % MOD;
    b >>= 1;
  }
  return ret;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  cin >> k;
  bool even = false;
  bool ones = true;
  for (int i = 1; i <= k; i++) {
    cin >> a[i];
    if (a[i] != 1) ones = false;
    if (a[i] % 2 == 0) even = true;
  }
  if (ones) {
    cout << "0/1" << endl;
    return 0;
  }
  long long p = 1;
  for (int i = 1; i <= k; i++) {
    p = (p * (a[i] % (MOD - 1))) % (MOD - 1);
  }
  long long num = (fast(2, p) * fast(2, MOD - 2)) % MOD;
  if (even) {
    num = (num + 1) % MOD;
  } else
    num = (num - 1 + MOD) % MOD;
  num = (num * fast(3, MOD - 2)) % MOD;
  long long den = ((fast(2, p) * fast(2, MOD - 2)) % MOD);
  cout << num << '/' << den << endl;
  return 0;
}
