import java.util.*;

public class Main {
    static final int MOD = 1000000007;
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        int k = sc.nextInt();
        int[] lefts = new int[m];
        int[] rights = new int[m];
        for (int i = 0; i < m; i++) {
            lefts[i] = sc.nextInt();
            rights[i] = sc.nextInt();
        }
        int[][] dp = new int[k + 1][n + 2];
        Arrays.fill(dp[0], 1);
        dp[0][0] = 0;
        for (int i = 1; i <= k; i++) {
            for (int j = 0; j < m; j++) {
                int sum = (dp[i - 1][rights[j]] - dp[i - 1][lefts[j] - 1] + MOD) % MOD;
                dp[i][lefts[j]] += sum;
                dp[i][lefts[j]] %= MOD;
                dp[i][rights[j] + 1] += MOD - sum;
                dp[i][rights[j] + 1] %= MOD;
            }
            for (int j = 1; j <= n; j++) {
                dp[i][j] += dp[i][j - 1];
                dp[i][j] %= MOD;
            }
            for (int j = 1; j <= n; j++) {
                dp[i][j] += dp[i][j - 1];
                dp[i][j] %= MOD;
            }
        }
        System.out.println((dp[k][n] - dp[k][n - 1] + MOD) % MOD);
    }
}