# C
import copy
N = int(input())

count = 0
A = [N]
B = []
while True:
    for i in range(len(A)):
        if A[i] < 3:
            count += 1
        else:
            B.append(int(A[i]/3))
        if A[i] < 5:
            count += 1
        else:
            B.append(int(A[i]/5))
    if len(B) == 0:
        break
    A = copy.deepcopy(B)
    B = []

print(count)