N, M = map(int, input().split())

diff = [M] * (N + 1)

for i in range(1, M + 1):
    for j in range(0, N + 1, i):
        diff[j] -= i

res = [0] * (N + 1)
for x in range(N):
    res[x + 1] = res[x] + diff[x + 1]
print(max(res))