import sys
input = sys.stdin.readline

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

def calc(x):
    ANS=x*M

    ind=1
    while ind<=M:
        k=x//ind
        if k==0:
            break
        MAX=x//k

        # [ind,MAX]

        MAX=min(MAX,M)

        ANS-=(ind+MAX)*(MAX-ind+1)*k//2
        ind=MAX+1

    return ANS

ANS=0

for i in range(N+1):
    ANS=max(ANS,calc(i))

print(ANS)