def primeset(N): #N以下の素数をsetで求める.エラトステネスの篩O(√Nlog(N))
    lsx = [1]*(N+1)
    for i in range(2,int(-(-N**0.5//1))+1):
        if lsx[i] == 1:
            for j in range(i,N//i+1):
                lsx[j*i] = 0
    setprime = set()
    for i in range(2,N+1):
        if lsx[i] == 1:
            setprime.add(i)
    return setprime
N,P = map(int,input().split())
if N <= 3:
    print(1)
    exit()
al = N//2
lsp = list(primeset(al))
lsp.sort()
ls = [0]*(N+1)
for p in lsp:
    st = 1
    while st*p <= N:
        ls[st*p] = 1
        st += 1
if ls[P] == 0:
    print(1)
else:
    print(sum(ls))