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.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Map.Entry;
import java.util.Queue;
import java.util.Scanner;
import java.util.Set;
import java.util.Stack;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.util.Vector;
 
 
 
public class coder {
	
	public static void main(String[] args) throws IOException{
		FastScanner sc = new FastScanner();
		   PrintWriter out = new PrintWriter(System.out);
		  long a =sc.nextLong();
		  long b=sc.nextLong();
		  long mod =(long) (1e9+7);
		  BigInteger ans =new BigInteger(b+"");
		  ans = ans.multiply(BigInteger.valueOf(b-1));
		  ans =ans.divide(BigInteger.valueOf(2));
		  
		  BigInteger x = new BigInteger(b+"");
		  x=x.multiply(BigInteger.valueOf(a));
		  x=x.multiply(BigInteger.valueOf(a+1));
		  x=x.divide(BigInteger.valueOf(2));
		  x =x.add(BigInteger.valueOf(a));
		  ans =ans.multiply(x);
		  ans =ans.mod(BigInteger.valueOf(mod));
		  System.out.println(ans);


		  
			   
			   
			   
			   
			   
		   
		 



}
	

}









	
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
class FastScanner {
 
 
 
 
    BufferedReader br;
    StringTokenizer st;
 
    public FastScanner() {
        br = new BufferedReader(new InputStreamReader(System.in));
    }
 
    public FastScanner(String s) {
        try {
            br = new BufferedReader(new FileReader(s));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
 
    String nextToken() {
        while (st == null || !st.hasMoreElements()) {
            try {
 
                st = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return st.nextToken();
    }
 
    int nextInt() {
        return Integer.parseInt(nextToken());
    }
 
    long nextLong() {
        return Long.parseLong(nextToken());
    }
 
    double nextDouble() {
        return Double.parseDouble(nextToken());
    }
 
 
}