func_code_string: #include <bits/stdc++.h>   using namespace std;   mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());   const int N = 200005;   const int M = 1000000007;   long long ast(long long x, long long n) {     x %= M;     long long ans = 1;     while (n) {       if (n % 2 == 1) ans = (ans * x) % M;       x = (x * x) % M;       n /= 2;     }     return ans;   }   int n;   long long a[N];   int main() {     scanf( %d , &n);     for (int i = 1; i <= n; ++i) scanf( %lld , &a[i]);     long long u = 2;     long long k = 1;     for (int i = 1; i <= n; ++i) {       u = ast(u, a[i]);       if (a[i] % 2 == 0) k = 0;     }     u = (u * ast(2, M - 2)) % M;     long long x;     if (k == 0)       x = ((u + 1) * ast(3, M - 2)) % M;     else       x = ((u - 1 + M) % M * ast(3, M - 2)) % M;     printf( %lld/%lld n , x, u);     return 0;   }   