import sys
input = sys.stdin.readline

N, M, K = map(int, input().split())
mod = 10 ** 9 + 7
L, R = [0] * M, [0] * M
for i in range(M):
    L[i], R[i] = map(int, input().split())
    L[i] -= 1

pre = [0] * N
pre[0] = 1
for _ in range(K):
    Ac = [0] * (N + 1)
    dp = [0] * (N + 1)
    ndp = [0] * (N + 1)
    for i in range(N):
        Ac[i + 1] = Ac[i] + pre[i]
        Ac[i + 1] %= mod
    
    for i in range(M):
        dp[L[i]] += Ac[R[i]] - Ac[L[i]]
        dp[R[i]] -= Ac[R[i]] - Ac[L[i]]
        dp[L[i]] %= mod
        dp[R[i]] %= mod

    ndp[0] = dp[0]
    for i in range(N):
        ndp[i + 1] = ndp[i] + dp[i + 1]
        ndp[i + 1] %= mod

    ndp, pre = pre, ndp

print(pre[N - 1]%mod)