/in/foo.cc: In function 'int sum(int**, int, int, int, int)':
/in/foo.cc:9:6: warning: variable 'down' set but not used [-Wunused-but-set-variable]
  int down = i;
      ^~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:85:36: warning: format '%ld' expects argument of type 'long int', but argument 2 has type 'long long int' [-Wformat=]
  printf("There are %ld ships.", res);
                                    ^