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.awt.Point;
import java.io.*;
import java.lang.reflect.Array;
import java.math.BigInteger;
import java.util.*;

import static java.lang.Math.*;

public class Main {

	final boolean ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE") != null;
	BufferedReader in;
	PrintWriter out;
	StringTokenizer tok = new StringTokenizer("");

	void init() throws FileNotFoundException {
		if (ONLINE_JUDGE) {
			in = new BufferedReader(new InputStreamReader(System.in));
			out = new PrintWriter(System.out);
		} else {
			in = new BufferedReader(new FileReader("input.txt"));
			out = new PrintWriter("output.txt");
		}
	}

	String readString() throws IOException {
		while (!tok.hasMoreTokens()) {
			tok = new StringTokenizer(in.readLine());
		}
		return tok.nextToken();
	}

	int readInt() throws IOException {
		return Integer.parseInt(readString());
	}

	long readLong() throws IOException {
		return Long.parseLong(readString());
	}

	double readDouble() throws IOException {
		return Double.parseDouble(readString());
	}

	public static void main(String[] args) {
		new Main().run();
		// Sworn to fight and die
	}

	public static void mergeSort(int[] a) {
		mergeSort(a, 0, a.length - 1);
	}

	private static void mergeSort(int[] a, int levtIndex, int rightIndex) {
		final int MAGIC_VALUE = 50;
		if (levtIndex < rightIndex) {
			if (rightIndex - levtIndex <= MAGIC_VALUE) {
				insertionSort(a, levtIndex, rightIndex);
			} else {
				int middleIndex = (levtIndex + rightIndex) / 2;
				mergeSort(a, levtIndex, middleIndex);
				mergeSort(a, middleIndex + 1, rightIndex);
				merge(a, levtIndex, middleIndex, rightIndex);
			}
		}
	}

	private static void merge(int[] a, int levtIndex, int middleIndex,
			int rightIndex) {
		int length1 = middleIndex - levtIndex + 1;
		int length2 = rightIndex - middleIndex;
		int[] levtArray = new int[length1];
		int[] rightArray = new int[length2];
		System.arraycopy(a, levtIndex, levtArray, 0, length1);
		System.arraycopy(a, middleIndex + 1, rightArray, 0, length2);
		for (int k = levtIndex, i = 0, j = 0; k <= rightIndex; k++) {
			if (i == length1) {
				a[k] = rightArray[j++];
			} else if (j == length2) {
				a[k] = levtArray[i++];
			} else {
				a[k] = levtArray[i] <= rightArray[j] ? levtArray[i++]
						: rightArray[j++];
			}
		}
	}

	private static void insertionSort(int[] a, int levtIndex, int rightIndex) {
		for (int i = levtIndex + 1; i <= rightIndex; i++) {
			int current = a[i];
			int j = i - 1;
			while (j >= levtIndex && a[j] > current) {
				a[j + 1] = a[j];
				j--;
			}
			a[j + 1] = current;
		}
	}

	public void run() {
		try {
			long t1 = System.currentTimeMillis();
			init();
			solve();
			out.close();
			long t2 = System.currentTimeMillis();
			System.err.println("Time = " + (t2 - t1));
		} catch (Exception e) {
			e.printStackTrace(System.err);
			System.exit(-1);
		}
	}

	class LOL implements Comparable<LOL> {
		int time;
		int num;
		int place;

		public LOL(int time, int num, int place) {
			this.time = time;
			this.num = num;
			this.place = place;
		}

		@Override
		public int compareTo(LOL o) {

			return (time - o.time); // ---->
			// return o.x * o.y - x * y; // <----
		}

	}

	public long gcd(long a, long b) {
		if (a % b == 0)
			return b;
		else
			return gcd(b, a % b);
	}

	public int gcd(int a, int b) {
		if (a % b == 0)
			return b;
		else
			return gcd(b, a % b);
	}

	boolean prime(int n) {
		for (int i = 2; i <= sqrt(n); i++)
			if (n % i == 0)
				return false;
		return true;
	}
int mod = 1000 * 1000 * 1000 + 7;

	public void solve() throws IOException {
		int a = readInt();
		int b = readInt();
		
		long sum = 0;
		
		for (int r = 1; r < b; r++) {
			int min = r;
			long plus = (((long)(a + 1) * (long)(a)) / 2 )% mod;
			plus = (plus * (long)r)  % mod;
			plus = (plus * (long)b)% mod;
			plus += ((long)a * (long)r) % mod;
			sum = (sum + plus) % mod;
			
		}
		
		out.print(sum);
	}
}
