import itertools
import sys
input = sys.stdin.readline

N,M,K=map(int,input().split())
LR=[list(map(int,input().split())) for i in range(M)]
mod=10**9+7

DP=[0]*(N+2)
DP[1]=1

for move in range(K):
    NDP=[0]*(N+2)
    SUM=list(itertools.accumulate(DP))


    for l,r in LR:
        x=SUM[r]-SUM[l-1]
        NDP[l]+=x%mod
        NDP[r+1]-=x%mod

    DP=list(itertools.accumulate(NDP))
        
print(DP[N]%mod)