n, m = map(int, input().split())
imos = [0] * (n + 10)

for i in range(2, m + 1):
    for j in range(0, n + 1, i):
        imos[j + 1] += 1
        if j + i + 1 < n + 10:
            imos[j + i] -= i
            imos[j + i + 1] += i - 1


for i in range(1, n + 2):
    imos[i] += imos[i - 1]


for i in range(1, n + 2):
    imos[i] += imos[i - 1]

print(max(imos[1 : n + 1]))