#include <bits/stdc++.h>

using namespace std;
using ll = long long;

int main() {
	const ll MOD = 1e9 + 7;
	int N, M, K;
	cin >> N >> M >> K;
	vector<ll> L(M);
	vector<ll> R(M);
	for (int i = 0; i < M; ++i) {
		cin >> L[i] >> R[i];
	}

	vector<vector<ll>> dp(K + 1, vector<ll>(N + 2, 0));
	dp[0][1] = 1;
	for (int k = 1; k <= K; ++k) {
		for (int i = 1; i <= N; ++i) {
			(dp[k - 1][i] += dp[k - 1][i - 1]) %= MOD;
		}
		for (int i = 0; i < M; ++i) {
			ll t = (dp[k - 1][R[i]] - dp[k - 1][L[i] - 1]) % MOD;
			dp[k][L[i]] = (dp[k][L[i]] + t) % MOD;
			dp[k][R[i] + 1] = (dp[k][R[i] + 1] - t + MOD) % MOD;
		}
		for (int i = 1; i <= N; ++i) {
			(dp[k][i] += dp[k][i - 1]) %= MOD;
		}
	}

	cout << dp[K][N] % MOD << endl;

	return 0;
}