/in/foo.cc: In function 'int main()':
/in/foo.cc:7:6: warning: unused variable 'xmin' [-Wunused-variable]
  int xmin=2,xmax; 
      ^~~~
/in/foo.cc:8:6: warning: unused variable 'cnt' [-Wunused-variable]
  int cnt=0;
      ^~~
/in/foo.cc: In function 'int gis(int)':
/in/foo.cc:15:6: warning: unused variable 'xmin' [-Wunused-variable]
  int xmin=2; 
      ^~~~
/in/foo.cc:32:4: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   x=x+2;
   ~^~~~