function Main(input) {
    input = input.split('\n')[0];
    qwww = "a	b	c	d	e	f	g	h	i	j	k	l	m	n	o	p	q	r	s	t	u	v	w	x	y	z";
    Alp = qwww.split("	");
    console.log(Alp[Alp.indexOf(input)+1]);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));