def isYearLeap(year):
	if year % 4 != 0:
		return False
	elif year % 100 != 0:
		return True
	elif year % 400 != 0:
		return False
	else:
		return True

#print(isYearLeap(2020))		

testdata = [1900, 2000, 2016, 1987, 2021, 2020]
testresults = [False, True, True, False, True, True]


for i in range(len(testdata)):
 	yr = testdata[i]
 	print(yr,"-> ",end="")
 	result = isYearLeap(yr)
 	if result == testresults[i]:
 		print("OK")
 	else:
 		print("Failed")