N,P = map(int,input().split())
l = [0]*(N+1)
for i in range(2,N+1):
    for j in range(i,N+1,i):
        l[j] += 1
count = N-1
for n in range(N//2+1,N+1):
    if l[n] == 1:
        count -= 1
if l[P] == 1:
    print(1)
else:
    print(count)