diff --git a/lab23.py b/lab23.py
new file mode 100644
index 0000000..5fbb60d
--- /dev/null
+++ b/lab23.py
@@ -0,0 +1,19 @@
+def is_year_leap(year):
+    if year % 4 == 0:
+        return True
+    else:
+        return False
+
+test_data = [1901, 2000, 2016, 1987]
+
+test_result = [False, True, True, False]
+
+for i in range(len(test_data)):
+    yr = test_data[i]
+    print(yr, "->", end="")
+    resutl = is_year_leap(yr)
+    
+    if resutl == test_result[i]:
+        print("OK")
+    else:
+        print("Failed")
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