#include <bits/stdc++.h>
long long MOD = 1e9 + 7;
long long qpow(long long a, long long p) {
  a = a % MOD;
  long long ans = 1;
  while (p > 0) {
    if (p & 1) ans = ans * a % MOD;
    a = a * a % MOD;
    p >>= 1;
  }
  return ans;
}
int k, p;
int main() {
  std::cin >> k;
  long long a = 1;
  int e = 1;
  for (int i = 0; i < k; i++) {
    long long x;
    scanf("%lld", &x);
    if (x % 2 == 0) e = 0;
    x %= (MOD - 1);
    a = (a * x) % (MOD - 1);
  }
  long long up, low;
  if (a == 0) a = MOD - 1;
  if (!e) {
    up = (1 + qpow(2, a - 1)) * qpow(3, MOD - 2) % MOD;
  } else {
    up = (qpow(2, a - 1) - 1 + MOD) * qpow(3, MOD - 2) % MOD;
  }
  low = qpow(2, a - 1);
  printf("%lld/%lld", up, low);
  return 0;
}
