import math

def time(n):
    """ Return the number of steps 
    necessary to calculate
    `print countdown(n)`"""
    steps = 0
    ret = 0
    ret = n*2
    print "dsd"
    steps = steps + ret/5
    if ret%5 != 0:
        steps = steps + 4
    else:
        steps = steps + 3
    return steps

def countdown(x):
    y = 0
    while x > 0:
        x = x - 5
        y = y + 1
    print y

print countdown(1)