# python template for atcoder1
import sys
sys.setrecursionlimit(10**9)
input = sys.stdin.readline

N, M, K = map(int, input().split())
elev = [list(map(int, input().split())) for _ in range(M)]

dp = [[0]*(N+2) for _ in range(K+1)]
dp[0][1] = 1

MOD = 10**9+7


def solve3():
    for k in range(K):
        for i in range(N+1):
            dp[k][i+1] += dp[k][i]
        for l, r in elev:
            su = dp[k][r]-dp[k][l-1]
            dp[k+1][l] += su
            dp[k+1][r+1] -= su
        for i in range(N+1):
            dp[k+1][i+1] += dp[k+1][i]
            dp[k+1][i] %= MOD


solve3()
print(dp[K][N])