N, M = map(int, input().split())
D = [M for _ in range(N+1)]

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

ans = [0 for _ in range(N+1)]
for i in range(N):
    ans[i+1] = ans[i]+D[i+1]

print(max(ans))