题解 | #判断字母#

import java.util.Scanner;
public class Main{
public static void main(String[] args){
Scanner input = new Scanner(System.in);
while(input.hasNext())
{
String Y = "YES";
String N = "NO";
char a = input.next().charAt(0);
if(a>='a'&&a<='z'||a>='A'&&a<='Z')
System.out.println(Y);
else
System.out.println(N);
}
}
}