#include <bits/stdc++.h>
using namespace std;
 
#define fi first
#define se second
#define pb push_back
using vi = vector <int>;
using ll = long long;
using vl = vector <ll>;
using pii = pair <int, int>;
//~ const ll mod = 998244353;
const ll mod = 1e9 + 7;
ll qpow(ll a, ll b, ll m = mod) { ll r = 1, t = a;
	for(; b; b /= 2) { if(b & 1) r = r * t % m; t = t * t % m; } return r; }

const int N = 3e3 + 11;
int l[N], r[N];

ll f[N], g[N];
ll s[N];

int main() {
	ios :: sync_with_stdio(false);
	
	int n, m, k; cin >> n >> m >> k;
	for(int i = 1; i <= m; i ++)
		cin >> l[i] >> r[i];
	
	f[1] = 1;
	for(int i = 0; i < k; i ++) {
		memset(g, 0, sizeof g);
		
		for(int j = 1; j <= n; j ++)
			f[j] = (f[j] + f[j - 1]) % mod;
		
		for(int j = 1; j <= m; j ++) {
			s[j] = (f[r[j]] - f[l[j] - 1]) % mod;
			g[l[j]] += s[j];
			g[r[j] + 1] -= s[j];
		}
		
		for(int j = 1; j <= n; j ++)
			g[j] = (g[j] + g[j - 1]) % mod;
		
		swap(f, g);
	}
	
	ll ans = f[n] % mod;
	if(ans < 0) ans += mod;
	cout << ans << '\n';
}