#include <bits/stdc++.h>
using namespace std;
inline long long rd() {
  long long x = 0, f = 1;
  char ch = getchar();
  while (!isdigit(ch)) {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (isdigit(ch)) x = x * 10 + (ch ^ 48), ch = getchar();
  return x * f;
}
const long long N = 100010;
const long long mod = 1e9 + 7;
long long n, a[N], sum = 1;
long long qpow(long long n, long long k) {
  k = (k % (mod - 1) + mod - 1) % (mod - 1);
  long long res = 1;
  while (k) {
    if (k & 1) res = 1ll * res * n % mod;
    n = 1ll * n * n % mod, k >>= 1;
  }
  return res;
}
const long long inv3 = qpow(3, mod - 2);
long long ans1, ans2;
signed main() {
  n = rd();
  for (long long i = 1; i <= n; ++i)
    a[i] = rd(), sum = sum * (a[i] % (mod - 1)) % (mod - 1);
  ans1 = (qpow(2, sum - 1) + ((sum & 1) ? -1 : 1)) % mod * inv3 % mod;
  ans2 = qpow(2, sum - 1);
  printf("%lld/%lld\n", ans1, ans2);
  return 0;
}
