n, m = map(int, input().split())
x = m
X = []
while x > 1:
    X.append(x)
    if x%2 == 0:
        x //= 2
    else:
        x = (x+1)//2
X.append(1)
X.reverse()
l = len(X)
if l <= n:
    ans = sum(X)+(n-l)
    print(ans)
    exit()
Y = [1]
for i in range(n-1):
    Y.append(Y[-1]*2)
print(sum(Y))