/in/foo.c: In function 'main':
/in/foo.c:7:10: warning: unused variable 'z' [-Wunused-variable]
  int x,y,z,sum,i,n; 
          ^
/in/foo.c:7:8: warning: unused variable 'y' [-Wunused-variable]
  int x,y,z,sum,i,n; 
        ^
/in/foo.c:7:6: warning: unused variable 'x' [-Wunused-variable]
  int x,y,z,sum,i,n; 
      ^