# https://yukicoder.me/problems/no/3136

def FizzBuzz16(i):
    if i % 15 == 0:
        return "FizzBuzz"
    elif i % 3 == 0:
        return "Fizz"
    elif i % 5 == 0:
        return "Buzz"
    else:
        return "%X" % i

def solve_(n):
    # 3の倍数の数を計算
    n3 = n // 3
    # 5の倍数の数を計算
    n5 = n // 5

    # nについて16進数で表現してみる
    n_digits = []
    while n > 0:
        n_digits.append(n % 16)
        n //= 16
    n_digits.reverse()

    # n以下の16進値の計算
    dp_count = [[[0] * 15 for _ in range(2)] for _ in range(2)]
    dp_count[0][0][0] = 1
    dp_length = [[[0] * 15 for _ in range(2)] for _ in range(2)]
    for m in n_digits:
        new_dp_count = [[[0] * 15 for _ in range(2)] for _ in range(2)]
        new_dp_length = [[[0] * 15 for _ in range(2)] for _ in range(2)]
        for less in range(2):
            for leader_zero in range(2):
                for mod15 in range(15):
                    count = dp_count[less][leader_zero][mod15]
                    legnth = dp_length[less][leader_zero][mod15]
                    if less == 0:
                        for l in range(m + 1):
                            new_leader_zero = (0 if l == 0  and leader_zero == 0 else 1)
                            if new_leader_zero == 0:
                                new_less = 1
                            else:
                                new_less = (1 if l < m else 0)
                            new_mod15 = (l + mod15) % 15
                            new_dp_count[new_less][new_leader_zero][new_mod15] += count
                            if new_leader_zero == 1:
                                new_dp_length[new_less][new_leader_zero][new_mod15] += legnth + count
                    else:
                        for l in range(16):
                            new_leader_zero = (0 if l == 0  and leader_zero == 0 else 1)
                            new_less = 1
                            new_mod15 = (l + mod15) % 15
                            new_dp_count[new_less][new_leader_zero][new_mod15] += count
                            if new_leader_zero == 1:
                                new_dp_length[new_less][new_leader_zero][new_mod15] += legnth + count
        dp_count = new_dp_count
        dp_length = new_dp_length

    ans_length = 4 * (n3 + n5)
    for less in range(2):
        for mod15 in range(15):
            if mod15 % 3 != 0 and mod15 % 5 != 0:
                ans_length += dp_length[less][1][mod15]
    return ans_length

                            
def solve2(N):
    # NについてFの数+Bの数がどれくらいあるか調べる
    # 3の倍数の数を計算
    n3 = N // 3
    # 5の倍数の数を計算
    n5 = N // 5

    # nについて16進数で表現してみる
    n_digits = []
    while N > 0:
        n_digits.append(N % 16)
        N //= 16
    n_digits.reverse()

    dp_count = [[0] * 15 for _ in range(2)]
    dp_count[0][0] = 1
    dp_score = [[0] * 15 for _ in range(2)]
    for m in n_digits:
        new_dp_count = [[0] * 15 for _ in range(2)]
        new_dp_score = [[0] * 15 for _ in range(2)]
        for less in range(2):
            for mod15 in range(15):
                count = dp_count[less][mod15]
                score = dp_score[less][mod15]
                if less == 0:
                    for l in range(m + 1):
                        new_less = (1 if l < m else 0)
                        new_mod15 = (l + mod15) % 15
                        new_dp_count[new_less][new_mod15] += count                        
                        if l in (11, 15):
                            new_dp_score[new_less][new_mod15] += score + count
                        else:
                            new_dp_score[new_less][new_mod15] += score
                else:
                    for l in range(16):
                        new_less = 1
                        new_mod15 = (l + mod15) % 15
                        new_dp_count[new_less][new_mod15] += count                        
                        if l in (11, 15):
                            new_dp_score[new_less][new_mod15] += score + count
                        else:
                            new_dp_score[new_less][new_mod15] += score
        dp_count = new_dp_count
        dp_score = new_dp_score
    
    answer = n3 + n5
    for less in range(2):
        for mod15 in range(15):
            if mod15 % 3 != 0 and mod15 % 5 != 0:
                answer += dp_score[less][mod15]
    return answer


def solve(Y):
    # 長さがY以上になるようなNの最小値をもとめる
    low = 1
    high = Y
    while high - low > 1:
        mid = (high + low) // 2
        if solve_(mid) >= Y:
            high = mid
        else:
            low = mid
    if solve_(low) >= Y:
        N = low
    else:
        N = high
    


    x = FizzBuzz16(N)
    length = solve_(N)
#    print(N, length, x)
    y = Y - (length - len(x))
    x0 = x[:y]
    answer = solve2(N - 1)
    for x in x0:
        if x in ("F", "B"):
            answer += 1
    return answer


def main():
    X = int(input())
    Y = int(input())

    ans = solve(Y)
    if X > 1:
        ans -= solve(X - 1)
    print(ans)







if __name__ == "__main__":
    main()