#include <bits/stdc++.h>
using namespace std;
const int MOD = (int)1e9 + 7;
const int INF = (int)1e9;
const long long LINF = (long long)1e18;
const long double PI = acos((long double)-1);
const long double EPS = 1e-9;
inline long long gcd(long long a, long long b) {
  long long r;
  while (b) {
    r = a % b;
    a = b;
    b = r;
  }
  return a;
}
inline long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
inline long long fpow(long long n, long long k, int p = MOD) {
  long long r = 1;
  for (; k; k >>= 1) {
    if (k & 1) r = r * n % p;
    n = n * n % p;
  }
  return r;
}
template <class T>
inline int chkmin(T& a, const T& val) {
  return a > val ? a = val, 1 : 0;
}
template <class T>
inline int chkmax(T& a, const T& val) {
  return a < val ? a = val, 1 : 0;
}
inline long long isqrt(long long k) {
  long long r = sqrt(k) + 1;
  while (r * r > k) r--;
  return r;
}
inline long long icbrt(long long k) {
  long long r = cbrt(k) + 1;
  while (r * r * r > k) r--;
  return r;
}
inline void addmod(int& a, int val, int p = MOD) {
  if ((a = (a + val)) >= p) a -= p;
}
inline void submod(int& a, int val, int p = MOD) {
  if ((a = (a - val)) < 0) a += p;
}
inline int mult(int a, int b, int p = MOD) { return (long long)a * b % p; }
inline int inv(int a, int p = MOD) { return fpow(a, p - 2, p); }
const int maxn = 100010;
int n;
long long a[maxn];
void solve() {
  cin >> n;
  int sum = 1, prd = 1;
  for (int i = (0); i < (n); i++) {
    cin >> a[i];
    sum = (long long)sum * (a[i] % 2) % 2;
    prd = mult(prd, a[i] % (MOD - 1), MOD - 1);
  }
  if (sum % 2 == 0) {
    int p = fpow(2, prd);
    p = mult(p, inv(2));
    int q = p;
    addmod(p, 1);
    p = mult(p, inv(3));
    cout << p << "/" << q << "\n";
  } else {
    int p = fpow(2, prd);
    p = mult(p, inv(2));
    int q = p;
    submod(p, 1);
    p = mult(p, inv(3));
    cout << p << "/" << q << "\n";
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  solve();
  return 0;
}
