mod = 1000000007
eps = 10**-9


def main():
    import sys
    from math import sqrt
    input = sys.stdin.buffer.readline

    L, R = map(int, input().split())
    N = 10 ** 6
    div = [[] for _ in range(N+1)]
    for d in range(2, N+1):
        for x in range(2, N+1):
            if d*x > N:
                break
            div[d*x].append(d)
    cnt = [0] * (N + 1)
    for d in range(N, 1, -1):
        cnt[d] += R // (d**2) - (L - 1) // (d**2)
        for e in div[d]:
            cnt[e] -= cnt[d]
    ans = R - (L - 1) - sum(cnt)
    for i in range(L, R+1):
        if i <= N**2:
            continue
        j = sqrt(i)
        for k in range(-2, 3):
            if j+k > 0:
                if (j+k) ** 2 == i:
                    ans -= 1
    print(ans)


if __name__ == '__main__':
    main()