N, M = map(int, input().split())
K = 505050
ans = [0] * K
for i in range(2, M + 1):
    for j in range(0, N + 1, i):
        ans[j] += 1
        ans[j + i - 1] -= i
        ans[j + i] += i - 1
    
for i in range(K - 1):
    ans[i + 1] += ans[i]
for i in range(K - 1):
    ans[i + 1] += ans[i]
print(max(ans[:N]))