/in/foo.c: In function 'main':
/in/foo.c:16:11: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long int' [-Wformat=]
  printf("%d",x);
           ^
/in/foo.c:14:9: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
   x=x*y/gcd(x,y);
         ^~~~~~~~
/in/foo.c: In function 'gcd':
/in/foo.c:31:9: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return s;
         ^