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

ans = []
for n in range(1, N+1):
    ans.append(n*max(M-n, 0))

for i in range(2, len(ans)):
    ans[i] += (1+(i-1))*(i-1)//2
    if i > M:
        diff = i-M
        ans[i] -= (1+diff)*diff//2
        
imos = [0]*N
for m in range(2, M+1):
    for n in range(2, 10**18):
        if m*n > N:
            break
        imos[m*n-1] += m
for i in range(1, N):
    imos[i] += imos[i-1]

for i in range(N):
    ans[i] -= imos[i]

print(max(ans))