#include <bits/stdc++.h>
#define rep(i,n) for(int i=(0);i<(n);i++)

using namespace std;

typedef long long ll;

template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);

	ll n, m, k;
	cin >> n >> m >> k;

	vector<ll> l(m), r(m);
	rep(i, m){
		cin >> l[i] >> r[i];
		l[i]--;
		r[i]--;
	} 

	ll MOD = 1e9 + 7;
	ll dp[k+1][n+1];
	rep(i, k+1) rep(j, n+1) dp[i][j] = 0;
	dp[0][0] = 1;

	rep(i, k){
		vector<ll> a(n+1, 0);
		rep(j, n) {
			a[j+1] = a[j] + dp[i][j];
			a[j+1] %= MOD;
		}

		rep(j, m){
			ll sm = a[r[j]+1] - a[l[j]];
			dp[i+1][l[j]] += sm;
			dp[i+1][l[j]] %= MOD;
			dp[i+1][r[j]+1] += MOD - sm;
			dp[i+1][r[j]+1] %= MOD;
		}

		rep(j, n){
			dp[i+1][j+1] += dp[i+1][j];
			dp[i+1][j+1] %= MOD;
		}
	}

	cout << dp[k][n-1] << endl;
}