/in/foo.cc: In function 'int main()':
/in/foo.cc:4:12: warning: unused variable 'max' [-Wunused-variable]
  int a,b,t,max,min,r;
            ^~~
/in/foo.cc:4:16: warning: unused variable 'min' [-Wunused-variable]
  int a,b,t,max,min,r;
                ^~~