/in/foo.cc: In function 'int main()':
/in/foo.cc:3:22: error: 'scanf' was not declared in this scope
  scanf("%d%d", &n, &v);
                      ^
/in/foo.cc:4:24: error: 'memset' was not declared in this scope
  memset(f, 0, sizeof(f));
                        ^
/in/foo.cc:12:40: error: 'max' was not declared in this scope
     f[j] = max(f[j], f[j-k*w[i]]+k*s[i]);
                                        ^
/in/foo.cc:16:21: error: 'printf' was not declared in this scope
  printf("%d\n", f[v]);
                     ^