for n in range(4, 1000):
    s = '3' + '5'*n
    while '25' in s or '355' in s or '555' in s:
        if '25' in s:
            s = s.replace('25', '32', 1)
        if '355' in s:
            s = s.replace('355', '25', 1)
        if '555' in s:
            s = s.replace('555', '3', 1)
    s = sum(int(d) for d in s)
    if s == 17:
        print(n)
        break