import numpy as np
import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)
mod = 10**9+7

n, m, k = map(int, input().split())
L, R = np.array([input().split() for _ in range(m)], dtype=np.int64).T

dp = np.ones(n+2, dtype=np.int64)
dp[0] = 0

for _ in range(k):
    newDP = np.zeros_like(dp)
    cnt = dp[R] - dp[L - 1]
    np.add.at(newDP, L, cnt)
    np.add.at(newDP, R + 1, -cnt)
    dp = np.cumsum(newDP) % mod
    dp = np.cumsum(dp) % mod


print((dp[n] - dp[n - 1]) % mod)