/in/foo.cc: In function 'bool check(int)':
/in/foo.cc:23:9: warning: unused variable 'tot' [-Wunused-variable]
     int tot=0;
         ^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:69:25: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
     printf("-1\n%d",ans);
                         ^