func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long inf = (1ll << 60);   const int maxn = 10010;   long long dp[2][maxn], c;   int p[maxn], s[maxn];   int n, id;   int main() {     scanf( %d%I64d , &n, &c);     for (int i = 0; i < n; i++) scanf( %d , p + i);     for (int i = 0; i < n; i++) scanf( %d , s + i);     for (int i = 1; i <= n; i++) dp[0][i] = inf;     for (int i = 0; i < n; i++) {       for (int j = 0; j <= i + 1; j++) dp[id ^ 1][j] = inf;       for (int j = 0; j <= i; j++) {         dp[id ^ 1][j] = min(dp[id ^ 1][j], dp[id][j] + p[i] + c * j);         dp[id ^ 1][j + 1] = min(dp[id ^ 1][j + 1], dp[id][j] + s[i]);       }       id ^= 1;     }     long long res = inf;     for (int i = 0; i <= n; i++) res = min(res, dp[id][i]);     cout << res << endl;     return 0;   }   