package jp.fedom.challange.yuki.q146;

import java.math.BigInteger;
import java.util.Scanner;

public class Main {
	static BigInteger t = BigInteger.ZERO;
	static BigInteger m = new BigInteger("1000000007");

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		while (sc.hasNext()) {
			solve(sc.nextLine());
		}
		t = t.mod(m);
		System.out.println(t.toString());

		sc.close();
	}

	public static void solve(String input) {
		if (input.split(" ").length == 1) {
			input = null;
			return;
		}
		String[] ss = input.split(" ");

	}
}