n,m,k=map(int,input().split())
e=[tuple(map(int,input().split())) for i in range(m)]
M=10**9+7
q=[0]*(n+1)
q[1]=1
for i in range(1,n+1):
  q[i]+=q[i-1]
for _ in range(k):
  nq=[0]*(n+1)
  for l,r in e:
    nq[l]+=q[r]-q[l-1]
    if r+1<=n:
      nq[r+1]-=q[r]-q[l-1]
  for i in range(1,n+1):
    nq[i]+=nq[i-1]
    nq[i]%=M
  for i in range(1,n+1):
    nq[i]+=nq[i-1]
    nq[i]%=M
  q=nq
print((q[n]-q[n-1])%M)