func_code_string: #include <bits/stdc++.h>   const int _ = 1e4 + 5;   const long long INF = 1ll << 60;   inline long long min(long long a, long long b) { return a < b ? a : b; }   int n, c, s[_], t[_];   long long dp[2][_];   int main() {     scanf( %d %d , &n, &c);     for (int i = 1; i <= n; ++i) scanf( %d , s + i);     for (int i = 1; i <= n; ++i) scanf( %d , t + i);     for (int i = 1; i <= n; ++i) {       memset(dp[i & 1], 0x3f, sizeof dp[i & 1]);       dp[i & 1][0] = dp[(i - 1) & 1][0] + s[i];       for (int j = 1; j <= i; ++j)         dp[i & 1][j] = min(dp[(i - 1) & 1][j] + 1ll * c * j + s[i],                            dp[(i - 1) & 1][j - 1] + t[i]);     }     long long ans = INF;     for (int i = 0; i <= n; ++i) ans = min(ans, dp[n & 1][i]);     printf( %lld n , ans);     return 0;   }   