import java.io.*;
import java.util.*;

public class Main {
    static final int MOD = 1000000007;
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int m = sc.nextInt();
        int k = sc.nextInt();
        int[] current = new int[n + 2];
        int[] next = new int[n + 2];
        Arrays.fill(current, 1);
        current[0] = 0;
        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();
        }
        while (k-- > 0) {
            for (int i = 0; i < m; i++) {
                int x = (current[rights[i]] - current[lefts[i] - 1] + MOD) % MOD;
                next[lefts[i]] += x;
                next[lefts[i]] %= MOD;
                next[rights[i] + 1] += MOD - x;
                next[rights[i] + 1] %= MOD;
            }
            for (int i = 1; i <= n; i++) {
                next[i] += next[i - 1];
                next[i] %= MOD;
            }
            for (int i = 1; i <= n; i++) {
                next[i] += next[i - 1];
                next[i] %= MOD;
            }
            int[] tmp = next;
            next = current;
            current = tmp;
            Arrays.fill(next, 0);
        }
        System.out.println((current[n] - current[n - 1] + MOD) % MOD);
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}