Dreamoon loves summing up something for no reason. One day he obtains two integers a and b occasionally. He wants to calculate the sum of all nice integers. Positive integer x is called nice if <image> and <image>, where k is some integer number in range [1, a].

By <image> we denote the quotient of integer division of x and y. By <image> we denote the remainder of integer division of x and y. You can read more about these operations here: http://goo.gl/AcsXhT.

The answer may be large, so please print its remainder modulo 1 000 000 007 (109 + 7). Can you compute it faster than Dreamoon?

Input

The single line of the input contains two integers a, b (1 ≤ a, b ≤ 107).

Output

Print a single integer representing the answer modulo 1 000 000 007 (109 + 7).

Examples

Input

1 1


Output

0


Input

2 2


Output

8

Note

For the first sample, there are no nice integers because <image> is always zero.

For the second sample, the set of nice integers is {3, 5}.
'''
Created on Oct 12, 2014

@author: nb
'''
def mpow(a,b,mod):
    if(b==0): return 1
    if(b==1): return a
    ans = mpow(a,int(b/2),mod)
    ans = ans*ans
    if(b%2==1):
        ans = ans*a
    ans = ans%mod
    return ans
def fun():
    l = list(map(int,raw_input().split()))
    a = l[0]
    b = l[1]
    mod = 1000000007
    p = (a)
    q = 2*(b+1)+(a-1)*b
    r = ((b*(b-1))/2)
    ans = (p*q*r)%mod
    ans = ans%mod
    ans = ans*pow(2,mod-2,mod);
    ans = ans%mod
    print(int(ans))

fun()