deleted:    app/src/main/java/com/example/xiangyi/sudoku1/About.java
	deleted:    app/src/main/java/com/example/xiangyi/sudoku1/Game.java
	deleted:    app/src/main/java/com/example/xiangyi/sudoku1/GameOver.java
	deleted:    app/src/main/java/com/example/xiangyi/sudoku1/SudokuSolver.java
	deleted:    app/src/main/java/com/example/xiangyi/sudoku1/TimeThread.java