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: Ismael
'''

#import time

MOD = 10**9+7
def sumTermsArith1(firstTerm,r,nbTerms):
    return (nbTerms*(2*firstTerm+(nbTerms-1)*r))//2

def solve(a,b):
    s = 0
    for rem in range(1,b):
        reason = rem*b
        s = (s+sumTermsArith1(reason+rem,reason,a))%MOD
    return s

def solve2(a,b):
    reason = a*(b*(a+1)+2)//2
    return sumTermsArith1(reason,reason,b-1)%MOD

#t = time.clock()
a,b = map(int,input().split())
#sol1 = solve(a,b)
sol2 = solve2(a,b)
print(sol2)
#print(sol1 == sol2)
#print(time.clock()-t)