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 and , where k is some integer number in range [1,a].By we denote the quotient of integer division of x and y. By 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 1000000007 (109+7). Can you compute it faster than Dreamoon?

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

Output Print a single integer representing the answer modulo 1000000007 (109+7).

For the first sample, there are no nice integers because is always zero.For the second sample, the set of nice integers is {3,5}.