import math
def roundDownNearest5(num):
return math.floor(num / 5) * 5
print(roundDownNearest5(13))
print(roundDownNearest5(14))
print(roundDownNearest5(16))
print(roundDownNearest5(7))
print(roundDownNearest5(3))
print(roundDownNearest5(4))
print(roundDownNearest5(5))
print(roundDownNearest5(-1))
print(roundDownNearest5(-9))
'''
run:
10
10
15
5
0
0
5
-5
-10
'''