/in/foo.c: In function 'main':
/in/foo.c:42:12: warning: unused variable 'k' [-Wunused-variable]
  int i,n,x,k;
            ^
/in/foo.c: In function 'Insert':
/in/foo.c:38:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^