import java.util.Scanner;

public class Main{
public static void main(String[] args){
Scanner scan=new Scanner(System.in);
String num=scan.next();
  
if(num.equals("a")){
    System.out.println("b");
}else if(num.equals("b")){
    System.out.println("c");
}else if(num.equals("c")){
    System.out.println("d");
}else if(num.equals("d")){
    System.out.println("e");
}else if(num.equals("e")){
    System.out.println("f");
}else if(num.equals("f")){
    System.out.println("g");
}else if(num.equals("g")){
    System.out.println("h");
}else if(num.equals("h")){
    System.out.println("i");
}else if(num.equals("i")){
    System.out.println("j");
}else if(num.equals("j")){
    System.out.println("k");
}else if(num.equals("k")){
    System.out.println("l");
}else if(num.equals("l")){
    System.out.println("m");
}else if(num.equals("m")){
    System.out.println("n");
}else if(num.equals("n")){
    System.out.println("o");
}else if(num.equals("o")){
    System.out.println("p");
}else if(num.equals("p")){
    System.out.println("q");
}else if(num.equals("q")){
    System.out.println("r");
}else if(num.equals("r")){
    System.out.println("s");
}else if(num.equals("s")){
    System.out.println("t");
}else if(num.equals("t")){
    System.out.println("u");
}else if(num.equals("u")){
    System.out.println("v");
}else if(num.equals("v")){
    System.out.println("w");
}else if(num.equals("w")){
    System.out.println("x");
}else if(num.equals("x")){
    System.out.println("y");
}else if(num.equals("y")){
    System.out.println("z");
}

}
}
/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