from itertools import accumulate
n, m, k = map(int, input().split())
mod = 10**9+7
t = [tuple(map(int, input().split())) for _ in range(m)]

#dp[x]
#i回目の移動でxにいる場合の数
dp = [0]*(n+1)
dp[1] = 1
for i in range(k):
    tmp = [0]*(n+2)
    dpac = list(accumulate(dp))
    for l, r in t:
        tmp[l] += dpac[r] - dpac[l-1]
        tmp[r+1] -= dpac[r] - dpac[l-1]

    dp = list(map(lambda x: x%mod, accumulate(tmp)))
print(dp[-2])