import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
	public static void main(String args[]) throws IOException {
		// 2020/1/30 No.151
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		String str = br.readLine();

		switch (str) {
		case "a":
			System.out.println("b");
			break;
		case "b":
			System.out.println("c");
			break;
		case "c":
			System.out.println("d");
			break;
		case "d":
			System.out.println("e");
			break;
		case "e":
			System.out.println("f");
			break;
		case "f":
			System.out.println("g");
			break;
		case "g":
			System.out.println("h");
			break;
		case "h":
			System.out.println("i");
			break;
		case "i":
			System.out.println("j");
			break;
		case "j":
			System.out.println("k");
			break;
		case "k":
			System.out.println("l");
			break;
		case "l":
			System.out.println("m");
			break;
		case "m":
			System.out.println("n");
			break;
		case "n":
			System.out.println("o");
			break;
		case "o":
			System.out.println("p");
			break;
		case "p":
			System.out.println("q");
			break;
		case "q":
			System.out.println("r");
			break;
		case "r":
			System.out.println("s");
			break;
		case "s":
			System.out.println("t");
			break;
		case "t":
			System.out.println("u");
			break;
		case "u":
			System.out.println("v");
			break;
		case "v":
			System.out.println("w");
			break;
		case "w":
			System.out.println("x");
			break;
		case "x":
			System.out.println("y");
			break;
		case "y":
			System.out.println("z");
			break;
		case "z":
			break;
		}
	}
}
/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