import bisect
import copy
import decimal
import fractions
import heapq
import itertools
import math
import random
import sys
import time
from collections import Counter,deque,defaultdict
from functools import lru_cache,reduce
from heapq import heappush,heappop,heapify,heappushpop,_heappop_max,_heapify_max
def _heappush_max(heap,item):
    heap.append(item)
    heapq._siftdown_max(heap, 0, len(heap)-1)
def _heappushpop_max(heap, item):
    if heap and item < heap[0]:
        item, heap[0] = heap[0], item
        heapq._siftup_max(heap, 0)
    return item
from math import gcd as GCD
read=sys.stdin.read
readline=sys.stdin.readline
readlines=sys.stdin.readlines
write=sys.stdout.write
class Cumsum:
    def __init__(self,lst,mod=0):
        self.N=len(lst)
        self.mod=mod
        self.cumsum=[0]*(self.N+1)
        self.cumsum[0]=0
        for i in range(1,self.N+1):
            self.cumsum[i]=self.cumsum[i-1]+lst[i-1]
            if self.mod:
                self.cumsum[i]%=self.mod

    def __getitem__(self,i):
        if type(i)==int:
            if 0<=i<self.N:
                a,b=i,i+1
            elif -self.N<=i<0:
                a,b=i+self.N,i+self.N+1
            else:
                raise IndexError('list index out of range')
        else:
            a,b=i.start,i.stop
            if a==None or a<-self.N:
                a=0
            elif self.N<=a:
                a=self.N
            elif a<0:
                a+=self.N
            if b==None or self.N<=b:
                b=self.N
            elif b<-self.N:
                b=0
            elif b<0:
                b+=self.N
        s=self.cumsum[b]-self.cumsum[a]
        if self.mod:
            s%=self.mod
        return s

    def __setitem__(self,i,x):
        if -self.N<=i<0:
            i+=self.N
        elif not 0<=i<self.N:
            raise IndexError('list index out of range')
        self.cumsum[i+1]=self.cumsum[i]+x
        if self.mod:
            self.cumsum[i+1]%=self.mod

    def __str__(self):
        lst=[self.cumsum[i+1]-self.cumsum[i] for i in range(self.N)]
        if self.mod:
            for i in range(self.N):
                lst[i]%=self.mod
        return "["+", ".join(map(str,lst))+"]"

N,M,K=map(int,readline().split())
L,R=[],[]
for _ in range(M):
    l,r=map(int,readline().split())
    l-=1
    L.append(l)
    R.append(r)
dp=[0]*N
dp[0]=1
mod=10**9+7
for k in range(K):
    prev=Cumsum(dp,mod=mod)
    imos=[0]*(N+1)
    for l,r in zip(L,R):
        imos[l]+=prev[l:r]
        imos[r]-=prev[l:r]
    for i in range(1,N+1):
        imos[i]+=imos[i-1]
        imos[i]%=mod
    dp=imos[:N]
ans=dp[N-1]
print(ans)