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.IOException;
import java.io.OutputStreamWriter;
import java.io.BufferedWriter;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.Writer;
import java.math.BigInteger;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author Mahmoud Aladdin <aladdin3>
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		OutputWriter out = new OutputWriter(outputStream);
		TaskC solver = new TaskC();
		solver.solve(1, in, out);
		out.close();
	}
}

class TaskC {

    final long MOD = (long)(1e9) + 7;
    long mod2Inv =  BigInteger.valueOf(2).modInverse(BigInteger.valueOf(MOD)).longValue();

    long arith(long a, long d, long n) {
        long part1 = ((2 * a) % MOD) + (((n - 1L) % MOD) * (d % MOD));
        long part2 = n % MOD;
        return ((part1 % MOD) * (part2 % MOD) % MOD) * mod2Inv;
    }


    public void solve(int testNumber, InputReader jin, OutputWriter jout) {
        int a = jin.int32();
        int b = jin.int32();

        long sum = 0;
        for(int k = 1; k <= a; k++) {
            sum += arith(1, 1, b - 1) % MOD;
            sum += b * (arith(k, k, b - 1) % MOD);
            sum %= MOD;
        }

        jout.println(sum);
    }
}

class InputReader {
    private static final int bufferMaxLength = 1024;
    private InputStream in;
    private byte[] buffer;
    private int currentBufferSize;
    private int currentBufferTop;
    private static final String tokenizers = " \t\r\f\n";
    
    public InputReader(InputStream stream) {
        this.in = stream;
        buffer = new byte[bufferMaxLength];
        currentBufferSize = 0;
        currentBufferTop = 0;
    }
    
    private boolean refill() {
        try {
            this.currentBufferSize = this.in.read(this.buffer);
            this.currentBufferTop = 0;
        } catch(Exception e) {}
        return this.currentBufferSize > 0;
    }
    
    
    private Byte readChar() {
        if(currentBufferTop < currentBufferSize) {
            return this.buffer[this.currentBufferTop++];
        } else {
            if(!this.refill()) {
                return null;
            } else {
                return readChar();
            }
        }
    }

    public String token()  {
        StringBuffer tok = new StringBuffer();
        Byte first;
        while((first = readChar()) != null && (tokenizers.indexOf((char) first.byteValue()) != -1));
        if(first == null) return null;
        tok.append((char)first.byteValue());
        while((first = readChar()) != null && (tokenizers.indexOf((char) first.byteValue()) == -1)) {
            tok.append((char)first.byteValue());
        }
        return tok.toString();
    }
    
    public Integer int32() throws NumberFormatException {
        String tok = token();
        return tok == null? null : Integer.parseInt(tok);
    }

    }

class OutputWriter {
    private final int bufferMaxOut = 1024;
    private PrintWriter out;
    private StringBuilder output;
    private boolean forceFlush = false;

    public OutputWriter(OutputStream outStream) {
        out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outStream)));
        output = new StringBuilder(2 * bufferMaxOut);
    }

    public OutputWriter(Writer writer) {
        forceFlush = true;
        out = new PrintWriter(writer);
        output = new StringBuilder(2 * bufferMaxOut);
    }

    private void autoFlush() {
        if(forceFlush || output.length() >= bufferMaxOut) {
            flush();
        }
    }

    public void print(Object... tokens) {
        for(int i = 0; i < tokens.length; i++) {
            if(i != 0) output.append(' ');
            output.append(tokens[i]);
        }
        autoFlush();
    }

    public void println(Object... tokens) {
        print(tokens);
        output.append('\n');
        autoFlush();
    }

    public void flush() {
        out.print(output);
        output.setLength(0);
    }

    public void close() {
        flush();
        out.close();
    }
}

