#include <bits/stdc++.h>
long long ja = 1, mo = 1;
long long a;
int n;
long long pow2a(long long y, long long x) {
  if (x == 0) return 1;
  long long sv = pow2a(y, x / 2);
  sv *= sv;
  sv %= 1000000007LL;
  if (x % 2) {
    sv *= y;
    sv %= 1000000007LL;
  }
  return sv;
}
int main() {
  scanf("%d", &n);
  int hol = 1;
  long long b = 2;
  for (int i = 0; i < n; i++) {
    scanf("%lld", &a);
    if (a % 2 == 0) hol = 0;
    b = pow2a(b, a);
  }
  if (b % 2)
    b = (b + 1000000007LL) / 2;
  else
    b = b / 2;
  long long res = b;
  mo = res;
  if (hol) {
    res += 1000000007LL - 1;
  } else {
    res += 1;
  }
  while (res % 3) {
    res += 1000000007LL;
  }
  res /= 3;
  res %= 1000000007LL;
  ja = res;
  printf("%lld/%lld\n", ja, mo);
}
