/in/foo.cc: In function 'bool check(int)':
/in/foo.cc:50:6: warning: unused variable 'u' [-Wunused-variable]
  int u,v,ta;
      ^
/in/foo.cc:50:8: warning: unused variable 'v' [-Wunused-variable]
  int u,v,ta;
        ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:86:8: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d",ans);
  ~~~~~~^~~~~~~~~~
/in/foo.cc:74:7: warning: 'ma' may be used uninitialized in this function [-Wmaybe-uninitialized]
  if(ma<0||mi>0)
     ~~^~
/in/foo.cc:74:13: warning: 'mi' may be used uninitialized in this function [-Wmaybe-uninitialized]
  if(ma<0||mi>0)
           ~~^~