l, r = map(int, input().split())


def lang(x):
    if 1 <= x <= 295:
        return 0
    if 296 <= x <= 416:
        return 1
    if 417 <= x <= 420:
        return 2


change = 0
p = lang(l)

for x in range(l + 1, r + 1):
    if p != lang(x):
        change += 1
    p = lang(x)

print(change)