import sys
input=sys.stdin.readline
def main2(n,m,k,lr):
  mod=10**9+7
  dp=[0]*(n+1)
  dp[1]=1
  now=0
  cnt_ary=[0]*(n+1)
  for l,r in lr:
    cnt_ary[l]+=1
    if r!=n:cnt_ary[r+1]-=1
  for i in range(n):cnt_ary[i+1]+=cnt_ary[i]
  for _ in range(k):
    ndp=[0]*(n+1)
    sdp=[0]
    for x in dp:sdp.append((sdp[-1]+x)%mod)
    mat0=[0]*(n+1)
    mat1=[0]*(n+1)
    for l,r in lr:
      mat0[r]+=sdp[r+1]-sdp[l]
      mat1[l]+=sdp[r+1]-sdp[l]

    # 下からの遷移。同じ階の移動も含む
    for j in range(1,n+1):
      # j階への遷移
      now+=cnt_ary[j]*dp[j]
      now%=mod
      ndp[j]+=now
      ndp[j]%=mod
      now-=mat0[j]
      now%=mod
    # 上からの遷移。同じ階の移動は含まない
    for j in reversed(range(1,n+1)):
      # j階への遷移
      ndp[j]+=now
      ndp[j]%=mod
      now+=cnt_ary[j]*dp[j]
      now-=mat1[j]
      now%=mod
    dp=ndp
  return dp[n]

if __name__=='__main__':
  n,m,k=map(int,input().split())
  lr=[list(map(int,input().split())) for _ in range(m)]
  ret2=main2(n,m,k,lr)
  print(ret2)