import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")
import copy

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	N, M, K = getlist()
	ele = []
	for i in range(M):
		L, R = getlist()
		L -= 1; R -= 1
		ele.append([L, R])
	
	DP = [[0] * (N + 1) for i in range(K + 1)]
	DP[0][1] = 1
	for i in range(K):
		# 累積和
		for j in range(N):
			DP[i][j + 1] += DP[i][j]
			DP[i][j + 1] %= con

		imos = [0] * (N + 1)
		for j in range(M):
			l, r = ele[j]
			val = DP[i][r + 1] - DP[i][l]
			imos[l] += val; imos[r + 1] -= val

		for j in range(N):
			imos[j + 1] += imos[j]
			imos[j + 1] %= con

		for j in range(N):
			DP[i + 1][j + 1] = imos[j]

	ans = DP[-1][-1]
	print(ans % con)


if __name__ == '__main__':
	main()