H, W = map(int,input().split())
if H == 0:
    print(0)
    exit(0)

W = abs(W)
t = W//H
q = W%H
if q == 0:
    ans = (t*H*(H+1))//2
else:
    ans = (t*H*(H+1))//2 + H-q + (q*(q+1))//2

print(ans)