/in/foo.cc: In function 'int make(int, int, int)':
/in/foo.cc:21:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'bool cmp(arr, arr)':
/in/foo.cc:24:29: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  return x.a<y.a || x.a==y.a && x.pos<y.pos;
                             ^