import sys
import numpy as np

input = sys.stdin.buffer.readline

N, M, K = map(int, input().split())
elv = np.array([tuple(map(int, input().split())) for _ in range(M)])
MOD = 10 ** 9 + 7

dp = np.zeros(N + 2, dtype=np.int64)
dp[1] = 1

for _ in range(K):
    acc = np.cumsum(dp)
    imos = np.zeros(N + 2, dtype=np.int64)
    S = acc[elv[:, 1]] - acc[elv[:, 0] - 1]
    np.add.at(imos, elv[:, 0], S)
    np.subtract.at(imos, elv[:, 1] + 1, S)
    dp = np.cumsum(imos) % MOD
print(dp[N])