/in/foo.cc: In function 'int Calc(int, int)':
/in/foo.cc:80:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:118:13: warning: unused variable 'lca' [-Wunused-variable]
     int x,y,lca;
             ^~~