File list (Check if you may need any files):
50\Program_41.class
..\Program_41.java
..\Program_42.class
..\Program_42.java
..\Program_43.class
..\Program_43.java
..\Program_44.class
..\Program_44.java
..\Program_45.class
..\Program_45.java
..\Program_46.class
..\Program_46.java
..\Program_47.class
..\Program_47.java
..\Program_48.class
..\Program_48.java
..\Program_49.class
..\Program_49.java
..\Program_50.class
..\Program_50.java
..\stud.txt
..\题50.txt
Java50编程练习.txt
10\Program_1.class
..\Program_1.java
..\Program_10.class
..\Program_10.java
..\Program_2.class
..\Program_2.java
..\Program_3.class
..\Program_3.java
..\Program_4.class
..\Program_4.java
..\Program_5.class
..\Program_5.java
..\Program_6.class
..\Program_6.java
..\Program_7.class
..\Program_7.java
..\Program_8.class
..\Program_8.java
..\Program_9.class
..\Program_9.java
..\题10.txt
20\Program_11(1).class
..\Program_11(1).java
..\Program_11(2).class
..\Program_11(2).java
..\Program_12.class
..\Program_12.java
..\Program_13.class
..\Program_13.java
..\Program_14.class
..\Program_14.java
..\Program_15.class
..\Program_15.java
..\Program_16.class
..\Program_16.java
..\Program_17.class
..\Program_17.java
..\Program_18.class
..\Program_18.java
..\Program_19.class
..\Program_19.java
..\Program_20.class
..\Program_20.java
..\题20.txt
30\Program_21.class
..\Program_21.java
..\Program_22.class
..\Program_22.java
..\Program_23.class
..\Program_23.java
..\Program_24.class
..\Program_24.java
..\Program_25.class
..\Program_25.java
..\Program_26.class
..\Program_26.java
..\Program_27.class
..\Program_27.java
..\Program_28.class
..\Program_28.java
..\Program_29.class
..\Program_29.java
..\Program_30.class
..\Program_30.java
..\题30.txt
40\Program_31.class
..\Program_31.java
..\Program_32.class
..\Program_32.java
..\Program_33.class
..\Program_33.java
..\Program_34.class
..\Program_34.java
..\Program_35.class
..\Program_35.java
..\Program_36.class
..\Program_36.java