import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String a = sc.next();
		char b = 'a';       
        if(a.equals("a")){b='b';}
           if(a.equals("b")){b='c';}                                      
           if(a.equals("c")){b='d';}                 
      if(a.equals("d")){b='e';}
      if(a.equals("e")){b='f';}
      if(a.equals("f")){b='g';}
      if(a.equals("g")){b='h';}
      if(a.equals("h")){b='i';}
      if(a.equals("i")){b='j';}
      if(a.equals("j")){b='k';}
      if(a.equals("k")){b='l';}
      if(a.equals("l")){b='m';}
      if(a.equals("m")){b='n';}
      if(a.equals("n")){b='o';}
      if(a.equals("o")){b='p';}
      if(a.equals("p")){b='q';}
      if(a.equals("q")){b='r';}
      if(a.equals("r")){b='s';}
      if(a.equals("s")){b='t';}
      if(a.equals("t")){b='u';}
      if(a.equals("u")){b='v';}
      if(a.equals("v")){b='w';}
      if(a.equals("w")){b='x';}
      if(a.equals("x")){b='y';}
      if(a.equals("y")){b='z';}
		System.out.println(b);
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz