#include "bits/stdc++.h"

using namespace std;

#define int long long
#define ll long long
typedef pair<int, int> P;
#define mod 1000000007
#define INF (1LL<<60)

#define rep(i,n) for(int i=0, i##_len=(n); i<i##_len; ++i)
#define YES cout << "YES" << endl;
#define Yes cout << "Yes" << endl;
#define NO cout << "NO" << endl;
#define No cout << "No" << endl;

int dp[3001][3001];
int sum[3001];


signed main(){

	int N, M, K;
	cin >> N >> M >> K;
	int L[3000], R[3000];
	rep(i, M){
		cin >> L[i] >> R[i];
		L[i]--; R[i]--;
	}

	dp[0][0] = 1;
	rep(k, K){
		rep(i, N+1) sum[i] = 0;
		rep(i, N) (sum[i + 1] = sum[i] + dp[k][i]) %= mod;
		rep(i, M){
			int sum_LR = sum[R[i]+1] - sum[L[i]];
			(dp[k+1][L[i]] += sum_LR)%=mod;
			(dp[k+1][R[i]+1] -= sum_LR)%=mod;
		}
		rep(i, N)
			(dp[k + 1][i + 1] += dp[k + 1][i])%=mod;
	}

	cout << (dp[K][N-1]+mod) % mod<< endl;


	return 0;
}