from collections import *
from functools import *
from itertools import *
from heapq import *
import sys,math
input = sys.stdin.readline

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 = [0]*(N+2)
    S = list(accumulate([0]+dp[i]))
    for l,r in LR:
        
        ds = S[r+1]-S[l]
        I[l] += ds
        I[r+1] -= ds
    
    I = list(accumulate(I))
    dp[i+1] = [i%mod for i in I[:N+1]]

print(dp[-1][N])