Remove warnigs.

src/main/java/lab/GameController.java

@@ -2,15 +2,10 @@
 
 import static java.util.Comparator.comparingInt;
 
-import java.io.BufferedReader;
 import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.FileReader;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.PrintWriter;
-import java.util.HashSet;
-import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.LinkedList;
 import java.util.List;