from itertools import accumulate
N, M, K = map(int, input().split())
mod = 10**9 + 7
LR = [tuple(map(int, input().split())) for _ in range(M)]
dp = [0] * (N + 2)
dp[1] = 1
for _ in range(K):
    dp1 = [0] * (N + 2)
    dpac = list(accumulate(dp))
    for l, r in LR:
        dp1[l] += dpac[r] - dpac[l - 1]
        dp1[r + 1] -= dpac[r] - dpac[l - 1]
    dp = list(map(lambda x: x % mod, accumulate(dp1)))
print(dp[-2])