func_code_string: #include <bits/stdc++.h>   using namespace std;   struct __s {     __s() {}     ~__s() {       long long n;       cin >> n;     }   } __S;   double mm, back, now, ans;   long long m, n;   double st(double x) {     double res = 1.0;     for (long long i = 0; i < (long long)(n - 1); i++) {       res *= x / m;     }     return res;   }   int main(void) {     cin >> m >> n;     mm = (double)m;     back = st(mm);     for (long long i = 0; i < (long long)(m); i++) {       mm -= 1.0;       now = st(mm);       double res = (mm + 1.0) * (back + (back - now) * mm) / m;       ans += res;       if (res < 1e-6) {         cerr << i <<   n ;         break;       }       back = now;     }     printf( %.10f  n , ans);     return 0;   }   