#include <iostream>
#include <vector>
#define llint long long
#define mod 1000000007

using namespace std;


llint n, m, k;
llint l[3005], r[3005];
llint dp[3005][3005];
llint sum[3005];

int main(void)
{
	cin >> n >> m >> k;
	for(int i = 0; i < m; i++) cin >> l[i] >> r[i];
	
	dp[0][1] = 1;
	for(int i = 1; i <= k; i++){
		for(int j = 1; j <= n; j++){
			sum[j] = sum[j-1] + dp[i-1][j];
			sum[j] %= mod;
		}
		for(int j = 0; j < m; j++){
			dp[i][l[j]] += (sum[r[j]] - sum[l[j]-1]) % mod, dp[i][l[j]] %= mod;
			dp[i][r[j]+1] += (mod - (sum[r[j]] - sum[l[j]-1]) % mod) % mod, dp[i][r[j]+1] %= mod;
		}
		for(int j = 1; j <= n; j++){
			dp[i][j] += dp[i][j-1];
			dp[i][j] %= mod;
		}
	}
	cout << dp[k][n] << endl;
	
	return 0;
}