#include <iostream>
using namespace std;

const long long mod = 1000000007;
long long N, M, K, L[3009], R[3009], dp[3009][3009];

int main() {
	cin >> N >> M >> K;
	for (int i = 1; i <= M; i++) cin >> L[i] >> R[i];

	for (int i = 1; i <= N; i++) dp[0][i] = 1;
	for (int i = 0; i < K; i++) {
		for (int j = 1; j <= M; j++) {
			long long E = dp[i][R[j]] - dp[i][L[j] - 1] + mod; E %= mod;
			dp[i + 1][L[j]] += E;
			dp[i + 1][R[j] + 1] -= E;
		}
		for (int j = 1; j <= N; j++) { dp[i + 1][j] += dp[i + 1][j - 1]; dp[i + 1][j] %= mod; }
		for (int j = 1; j <= N; j++) { dp[i + 1][j] += dp[i + 1][j - 1]; dp[i + 1][j] %= mod; }
	}
	cout << (dp[K][N] - dp[K][N - 1] + mod) % mod << endl;
	return 0;
}