#yuki801
import itertools

mod=10**9+7
n,m,k=map(int,input().split())
lr=[]
for i in range(m):
 lr.append(list(map(int,input().split())))

dp=[0]*(n+1)
dp[1]=1
for i in range(k):
 t=[0]*(n+2)
 da=list(itertools.accumulate(dp))
 for l,r in lr:
  t[l]+=da[r]-da[l-1]
  t[r+1]-=da[r]-da[l-1]
 dp=list(map(lambda x:x%mod,itertools.accumulate(t)))
print(dp[-2])