import java.util.Scanner;

public class Main {
    public static void main(String...args){
        Scanner scanner=new Scanner(System.in);
        char next =scanner.next().charAt(0);
        if(next=='z'){
            System.out.println("z");
        }
        int u=(int)next;
        u=u+1;
        char result=(char)u;
        System.out.println(result);
    }
}


/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