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}.
import java.io.*;
import java.math.BigInteger;
import java.util.*;

public class check {

    /**
     * @param args
     * @throws IOException 
     */
    public static long Mod =  1000000007;
    public static void main(String[] args) throws IOException {
        // TODO Auto-generated method stub
        
        BufferedReader k=new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer str=new StringTokenizer(k.readLine());
        
        long a = Long.parseLong(str.nextToken());
        long b = Long.parseLong(str.nextToken());
        
        long res = 0;
        BigInteger A = BigInteger.valueOf(a);
        BigInteger sum0 = A.multiply(A.add(BigInteger.ONE));
        
        sum0 = sum0.remainder(BigInteger.valueOf(Mod));
        sum0 = sum0.divide(BigInteger.valueOf(2));
        long sum = ((a *(a+1))/ 2)%Mod;
        long x= ((a*(a+1))/2)%Mod;
        for (int i = 0; i < b; i++) {
            long temp = (a%Mod*i%Mod)%Mod + (((b%Mod*i%Mod)%Mod)*sum%Mod)%Mod;
            res += temp;
            res%=Mod;
            //System.out.println(temp);
            
        }
        System.out.println(res);

    }

}
