import math

a, b = map(int, input().split())
x, l, r = map(int, input().split())

#u = [list(range(a, b))]

def divide(a,b,x):
    return list(range((math.floor(a/x)+1)*x,b,x))

def count(li):
    total = 0
    for number in li:
        for digit in str(number):
            total += int(digit)
    return total

def count_to_single(num):
    while num>9:
        num = sum(int(i) for i in str(num))
    return num

print(count_to_single(count(divide(a, b, x))))