import java.util.Scanner;

 public class Main {

  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
       String C=sc.nextLine();
       String alp="abcdefghijklmnopqrstuvwxyz";
       int X=alp.indexOf(C);

      System.out.println(alp.charAt(X+1));

    }
  }
/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