java简单解法

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String str = in.nextLine();
        //根据空格进行split
        String[] array = str.split("\\s");
        //输出最后一个元素的长度
        System.out.println(array[array.length - 1].length());
    }
}