# いもす
N,M,K = map(int, input().split())
lsLR = [tuple(map(int,input().split())) for i in range(M)]
mod = 10**9+7
dp = [0]*(N+2)
dp[1] = 1
for i in range(K):
    imos = [0]*(N+2)
    for j in range(1,N+2):
        imos[j] = (imos[j-1]+dp[j])%mod
    dp = [0]*(N+2)
    for j in range(M):
        l,r = lsLR[j]
        cnt = (imos[r]-imos[l-1])%mod
        dp[l] += cnt
        dp[r+1] -= cnt
    for j in range(1,N+2):
        dp[j] = (dp[j-1]+dp[j])%mod
print(dp[-2]%mod)