from math import comb
data=input().split()
n=int(data[0])
k=int(data[1])

count=0
for i in range(2,n+1):
    r=(i+1)//2
    if comb(i,r)>k:
        if i%2==0:
            count+=1
            r=r-1
        else:
            count+=2
            r=r-2

        while comb(i,r)>k:
            count+=2
            r+=-1
            if r<0:
                break

print(count)