/in/foo.c: In function 'main':
/in/foo.c:7:10: warning: unused variable 'z' [-Wunused-variable]
  int x,y,z,k;
          ^
/in/foo.c:7:6: warning: unused variable 'x' [-Wunused-variable]
  int x,y,z,k;
      ^
/in/foo.c:23:2: warning: 'j' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d %d",s,j);
  ^~~~~~~~~~~~~~~~~~~
/in/foo.c:23:2: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]