func_code_string: #include <bits/stdc++.h>   using namespace std;   int v[1000005];   long long int l[1000005];   long long int r[1000005];   int main(void) {     int n, m;     int sum;     scanf(  %d %d , &n, &m);     for (int i = 0; i < n; i++) {       scanf(  %d , &v[i]);     }     l[0] = 0;     sum = 0;     for (int i = 1; i < n; i++) {       sum++;       int trip = (sum + m - 1) / m;       l[i] = l[i - 1] + 1LL * trip * (v[i] - v[i - 1]);     }     r[n - 1] = 0;     sum = 0;     for (int i = n - 2; i >= 0; i--) {       sum++;       int trip = (sum + m - 1) / m;       r[i] = r[i + 1] + 1LL * trip * (v[i + 1] - v[i]);     }     long long int res = l[0] + r[0];     for (int i = 0; i < n; i++) {       res = min(res, l[i] + r[i]);     }     printf( %lld n , 2 * res);     return 0;   }   