n=int(input())
a=[n]
while a.count(0)!=len(a):
    s=[]
    for i in range(0,len(a)):
        if a[i]!=0:
            s.append(int(a[i]/3))
            s.append(int(a[i]/5))
        else:
            s.append(0)
    else:
        a=s
print(len(a))