import java.util.Scanner;

class Main{
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        char C = scanner.next().charAt(0);

        /* int m = scanner.nextInt(); */

        char[] alpha = new char[26];
        for (int i = 0; i < 26; i++) {
            alpha[i] = (char) (97 + i);
        }

        int j;
        for (j = 0; j < alpha.length; j++) {
            if (C == alpha[j]) {
                System.out.println(alpha[j + 1]);
                return;
            }

        }

    }
}

/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