A,B = map(int,input().split())
mod = 10**9+7
if (A+B)%2==0:
    if A<B:
        A,B= B,A
    print((2*(B+1)**2-(2*B+1)+(2*B+1)*(A-B))%mod)
else:
    print((2*(B+1)**2-(2*B+1)+(2*B+1)*(A-B)-1)%mod)