func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = 3010;   int a[MAXN], b[MAXN], c[MAXN];   int d[MAXN][2];   int main() {     int n;     while (~scanf( %d , &n)) {       for (int i = 1; i <= n; ++i) scanf( %d , &a[i]);       for (int i = 1; i <= n; ++i) scanf( %d , &b[i]);       for (int i = 1; i <= n; ++i) scanf( %d , &c[i]);       d[1][0] = b[1];       d[1][1] = a[1];       for (int i = 2; i <= n; ++i) {         d[i][0] = max(d[i - 1][0] + b[i], d[i - 1][1] + c[i]);         d[i][1] = max(d[i - 1][0] + a[i], d[i - 1][1] + b[i]);       }       printf( %d n , d[n][1]);     }     return 0;   }   