/in/foo.cc: In function 'int main()':
/in/foo.cc:4:12: warning: unused variable 'mx' [-Wunused-variable]
  int a,cnt,mx,mn,g,s,b;
            ^~
/in/foo.cc:4:15: warning: unused variable 'mn' [-Wunused-variable]
  int a,cnt,mx,mn,g,s,b;
               ^~
/in/foo.cc:23:11: warning: 'cnt' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<cnt;
           ^