import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.math.BigDecimal;
import java.text.DecimalFormat;
import java.util.AbstractMap;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Deque;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;

import static java.util.Comparator.*;				

public class Main {
	
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        MyInput in = new MyInput(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        
        Solver solver = new Solver();
        solver.solve(1, in, out);
        
        out.close();
    }
    
    // ======================================================================
    //　１階からＮ階まで、エレベータを使って、Ｋ回で移動する　通りの数を計算する
    // 配るＤＰ（普通　→　これでは間に合わない）
    
    static class Solver {
    	int MOD = 1000000007;
    	
    	long[][] dp;
    	public void solve(int testNumber, MyInput in, PrintWriter out) {
    		int N = in.nextInt();						// 最上階（ゴール）
    		int M = in.nextInt();						// エレベータの数
    		int K = in.nextInt();						// 移動回数
    		int[] L = new int[M];						// エレベータの止まる階　ここから
    		int[] R = new int[M];						// エレベータの止まる階　ここまで
    		for(int i=0; i < M; i++) {
    			L[i] = in.nextInt();
    			R[i] = in.nextInt();
    		}
    		dp = new long[K+1][N+1];					// 移動数、現在の階数　→　スタートからここまでの通りの数
    		
    		long wk, wk2;
    		long[] wa = new long[N+1];					// 累積和の計算用
    		dp[0][1] = 1;								// 初期値(移動回数０の１階は　１）
    		for(int i=0; i < K; i++) {					// 移動回数
    			// 止まる階数の通りの数の　累積和を計算する
    			Arrays.fill(wa, 0);
    			for(int x=1; x < N+1; x++) {
    				wa[x] += wa[x-1] + dp[i][x];
//    				wa[x] %= MOD;
//    				out.println(" wa[" + x + "] = " + wa[x] + "  <--  dp[" + i + "][" + x + "] = " + dp[i][x]);
    			}
    			for(int j=0; j < M; j++) {				// エレベータ数
    				// wk2 = 0;
    				// for(int k=L[j]; k <= R[j]; k++) {	// エレベータの止まる階数分
    				// 	wk2 += dp[i][k];					// 一台分のスタートからここまでの通りの数の合計
    				// 	wk2 %= MOD;
    				// }
    				wk = wa[R[j]] - wa[L[j]-1];
    				wk %= MOD;
    				// if(wk2 != wk)
        // 				out.println(" 不一致  元 = " + wk2 + "  累積和 = " + wk + "  L[" + j + "] = " + L[j] + "  R[" + j + "] = " + R[j]);

    				for(int k=L[j]; k <= R[j]; k++) {	// エレベータの止まる階数分
    					dp[i+1][k] += wk;				// 通りの数の合計を　止まる階　全部に足す
    					dp[i+1][k] %= MOD;
    				}
    			}
    		}
    		out.println(dp[K][N]);						// Ｋ回移動して、Ｎ階につく　スタートからの通りの数
        }
    }

    static class PPP {
    	public int key, val;
    	public PPP(int key, int val) {
    		this.key = key;
    		this.val = val;
    	}
		public int getKey() {
			return key;
		}
		public void setKey(int key) {
			this.key = key;
		}
		public int getVal() {
			return val;
		}
		public void setVal(int val) {
			this.val = val;
		}
    }
    // ======================================================================
    static class Pair<K, V> extends AbstractMap.SimpleEntry<K, V> {
        /** serialVersionUID. */
        private static final long serialVersionUID = 6411527075103472113L;

        public Pair(final K key, final V value) {
            super(key, value);
        }
     }    
    static class MyInput {
        private final BufferedReader in;
        private static int pos;
        private static int readLen;
        private static final char[] buffer = new char[1024 * 8];
        private static char[] str = new char[500 * 8 * 2];
        private static boolean[] isDigit = new boolean[256];
        private static boolean[] isSpace = new boolean[256];
        private static boolean[] isLineSep = new boolean[256];
 
        static {
            for (int i = 0; i < 10; i++) {
                isDigit['0' + i] = true;
            }
            isDigit['-'] = true;
            isSpace[' '] = isSpace['\r'] = isSpace['\n'] = isSpace['\t'] = true;
            isLineSep['\r'] = isLineSep['\n'] = true;
        }
 
        public MyInput(InputStream is) {
            in = new BufferedReader(new InputStreamReader(is));
        }
 
        public int read() {
            if (pos >= readLen) {
                pos = 0;
                try {
                    readLen = in.read(buffer);
                } catch (IOException e) {
                    throw new RuntimeException();
                }
                if (readLen <= 0) {
                    throw new MyInput.EndOfFileRuntimeException();
                }
            }
            return buffer[pos++];
        }
 
        public int nextInt() {
            int len = 0;
            str[len++] = nextChar();
            len = reads(len, isSpace);
            int i = 0;
            int ret = 0;
            if (str[0] == '-') {
                i = 1;
            }
            for (; i < len; i++) ret = ret * 10 + str[i] - '0';
            if (str[0] == '-') {
                ret = -ret;
            }
            return ret;
        }
 
        public long nextLong() {
            int len = 0;
            str[len++] = nextChar();
            len = reads(len, isSpace);
            int i = 0;
            long ret = 0L;
            if (str[0] == '-') {
                i = 1;
            }
            for (; i < len; i++) ret = ret * 10 + str[i] - '0';
            if (str[0] == '-') {
                ret = -ret;
            }
            return ret;
        }
 
       public String nextString() {
        	String ret = new String(nextDChar()).trim();
            return ret;
        }
 
        public char[] nextDChar() {
            int len = 0;
            len = reads(len, isSpace);
            char[] ret = new char[len + 1];
            for (int i=0; i < len; i++)		ret[i] = str[i];
            ret[len] = 0x00;
            return ret;
        }
 
        public char nextChar() {
            while (true) {
                final int c = read();
                if (!isSpace[c]) {
                    return (char) c;
                }
            }
        }
 
        int reads(int len, boolean[] accept) {
            try {
                while (true) {
                    final int c = read();
                    if (accept[c]) {
                        break;
                    }
                    if (str.length == len) {
                        char[] rep = new char[str.length * 3 / 2];
                        System.arraycopy(str, 0, rep, 0, str.length);
                        str = rep;
                    }
                    str[len++] = (char) c;
                }
            } catch (MyInput.EndOfFileRuntimeException e) {
            }
            return len;
        }
 
        static class EndOfFileRuntimeException extends RuntimeException {
        }
    }
}