diff --git a/doc/iter1/iter1.pdf b/doc/iter1/iter1.pdf
new file mode 100644
index 0000000000000000000000000000000000000000..c6f1d11d7c0a81d902446bed85dde545cd9ea746
Binary files /dev/null and b/doc/iter1/iter1.pdf differ
diff --git a/src/main/java/org/example/exam/Exam.java b/src/main/java/org/example/exam/Exam.java
index 7eb689d8346c03d3d804c4c8fef39f67f1ec4892..db0f038b82fcd281ec026e1358512e0feb4ac707 100644
--- a/src/main/java/org/example/exam/Exam.java
+++ b/src/main/java/org/example/exam/Exam.java
@@ -8,7 +8,7 @@ import java.io.File;
 public abstract class Exam {
     protected int id;
     protected String title;
-    protected Long startTime;
-    protected Long endTime;
+    protected long startTime;
+    protected long endTime;
     protected Question[] questions;
 }