from collections import *
from functools import *
from itertools import *
from heapq import *
import sys,math
input = sys.stdin.readline
class RSQandRAQ():
    """区間加算、区間取得クエリをそれぞれO(logN)で答える
    add: 区間[l, r)にvalを加える
    query: 区間[l, r)の和を求める
    l, rは0-indexed
    """

    def __init__(self, n):
        self.n = n
        self.bit0 = [0] * (n + 1)
        self.bit1 = [0] * (n + 1)

    def _add(self, bit, i, val):
        i = i + 1
        while i <= self.n:
            bit[i] += val
            i += i & -i

    def _get(self, bit, i):
        s = 0
        while i > 0:
            s += bit[i]
            i -= i & -i
        return s

    def add(self, l, r, val):
        """区間[l, r)にvalを加える"""
        self._add(self.bit0, l, -val * l)
        self._add(self.bit0, r,  val * r)
        self._add(self.bit1, l,  val)
        self._add(self.bit1, r, -val)

    def query(self, l, r):
        """区間[l, r)の和を求める"""
        return self._get(self.bit0, r) + r * self._get(self.bit1, r) \
            - self._get(self.bit0, l) - l * self._get(self.bit1, l)
N,M,K = map(int,input().split())
mod = 10**9 + 7


LR = [tuple(map(int,input().split())) for _ in range(M)]

dp = [[0]*(N+1) for _ in range(K+1)]
dp[0][1] = 1
for i in range(K):
    
    I = RSQandRAQ(N+1)
    S = list(accumulate([0]+dp[i]))
    for l,r in LR:
        
        I.add(l,r+1,S[r+1]-S[l])
    
    for j in range(1,N+1):
        
        dp[i+1][j] = I.query(j,j+1)%mod

print(dp[-1][N])