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