from itertools import accumulate
import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)
mod = 10**9+7

n, m, k = map(int, input().split())
LR = tuple(tuple(map(int, input().split())) for _ in range(m))

dp = [1] * (n + 2)
dp[0] = 0

for _ in range(k):
    newDP = [0] * (n + 2)
    for l, r in LR:
        cnt = dp[r] - dp[l - 1]
        newDP[l] += cnt
        newDP[r + 1] -= cnt
    dp = list(accumulate(newDP))
    dp = list(accumulate(dp))
    for i in range(len(dp)):
        dp[i] %= mod

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