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}.
/*
@@@@@@@@@@@@@@@@@@@@@@@@
@@@ Akhmedov Doston  @@@
@@@@@@@@@@@@@@@@@@@@@@@@
  @@              @@
  
*/

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.Locale;
import java.util.StringTokenizer;

public class r_272_c {
	static BufferedReader br;
	static PrintWriter pw;
	static StringTokenizer st;
	public static void main(String[] args)throws IOException {
		Locale.setDefault(Locale.US);
		br=new BufferedReader(new InputStreamReader(System.in));
		pw=new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
		
		//gfile();
		long a=nextLong(),b=nextLong();
		long mod=1000000007,s=((1+a)*a/2),ans=0,y=0;
		s%=mod;
		for (int i = 1; i < b; i++) {
			y=s*b%mod;
			y=y*i%mod;
			ans+=(y+i*a)%mod;
		}
		pw.print(ans%mod);
		pw.close();
	}
	private static void gfile() throws IOException{
		br=new BufferedReader(new FileReader(new File("input.txt")));
		pw=new PrintWriter(new BufferedWriter(new FileWriter("output.txt")));
	}
	private static long nextLong()throws IOException {
		return Long.parseLong(next());
	}
	private static double nextDouble()throws IOException {
		return Double.parseDouble(next());
	}
	private static int nextInt()throws IOException {
		return Integer.parseInt(next());
	}
	private static String next()throws IOException{
		while(st==null||!st.hasMoreTokens())
			st=new StringTokenizer(br.readLine());
		return st.nextToken();
	}
}
