老师给的家庭作业，编写一段java代码运行，并且写出结果：题目一：求100之内的素数，题目二：请输入星期几的第一个字母来判断一下是星期几，如果第一个字母一样，则继续    判断第二个字母。-Homework teacher to write a java code to run, and write the results: Topic: seeking 100 primes, Topic 2: Please enter the first letter of the week to determine is the day of the week, if the first letter, as you continue to judge the second letter.