/in/foo.cc: In function 'bool solve()':
/in/foo.cc:9:6: warning: unused variable 'k' [-Wunused-variable]
  int k = 0;
      ^
/in/foo.cc:34:30: warning: 'mp' may be used uninitialized in this function [-Wmaybe-uninitialized]
  if(ns[mp - 1] > ms || ns[mp + 1] < ms)
                           ~~~^~~