"""

https://yukicoder.me/problems/no/801

推移先が区間なので、推移を簡略化できる

"""

mod = 10**9+7

N,M,K = map(int,input().split())

LR = []
for i in range(M):
    L,R = map(int,input().split())
    LR.append( (L-1,R-1) )

dp = [0] * N
dp[0] = 1

for _ in range(K):

    # 推移元累積輪
    S = [i for i in dp]
    for i in range(len(S)-1):
        S[i+1] += S[i]
        S[i+1] %= mod
    S.append(0)

    # 推移先
    ndp = [0] * N

    for l,r in LR:
        now = (S[r] - S[l-1]) % mod
        ndp[l] += now
        ndp[l] %= mod

        if r+1 < len(ndp):
            ndp[r+1] -= now
            ndp[r+1] %= mod

    for i in range(len(ndp)-1):
        ndp[i+1] += ndp[i]
        ndp[i+1] %= mod

    dp = ndp

print (dp[N-1] % mod)