#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<complex>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
using namespace std;
typedef long long ll;
typedef unsigned int ui;
const ll mod = 1000000007;
typedef long double ld;
const ld INF = (ld)10000000000000;
typedef pair<int, int> P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
typedef complex<ld> Point;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<ld, ld> LDP;
typedef pair<ll, ll> LP;
ll dp[3000];
ll cop[3001];

int main() {
	dp[0] = 1;
	int n, m, k; cin >> n >> m >> k;
	vector<int> l(m), r(m);
	rep(i, m) {
		cin >> l[i] >> r[i]; l[i]--; r[i]--;
	}
	rep(i, k) {
		fill(cop, cop + n, 0);
		rep(j, n) {
			rep(i2, m) {
				if (j < l[i2] || r[i2] < j)continue;
				(cop[l[i2]] += dp[j]) %= mod;
				(cop[r[i2] + 1] += mod - dp[j]) %= mod;
			}
		}
		rep(j, n) {
			(cop[j + 1] += cop[j]) %= mod;
		}
		rep(j, n)dp[j] = cop[j];
	}
	cout << dp[n - 1] << endl;
	//stop
	return 0;
}