#include <bits/stdc++.h>
using namespace std;

typedef pair<int, int> pii;
typedef long long ll;
typedef vector<int> vi;

#define pb push_back
#define eb emplace_back
#define mp make_pair
#define fi first
#define se second
#define rep(i,n) rep2(i,0,n)
#define rep2(i,m,n) for(int i=m;i<(n);i++)
#define ALL(c) (c).begin(),(c).end()
#define dump(x) cout << #x << " = " << (x) << endl
constexpr ll TEN(int n) { return (n == 0) ? 1 : 10 * TEN(n-1); }

template<class T, class U>
ostream& operator<<(ostream& os, const pair<T, U>& p) {
	os<<"("<<p.first<<","<<p.second<<")";
	return os;
}

template<class T>
ostream& operator<<(ostream& os, const vector<T>& v) {
	os<<"{";
	rep(i, v.size()) {
		if (i) os<<",";
		os<<v[i];
	}
	os<<"}";
	return os;
}

const ll MOD = 1000000007;
const int MX = 3010;

ll dp[MX][MX], pref[MX];
int L[MX], R[MX];
vi in[MX], out[MX];

int main() {
	int N, M, K;
	cin >> N >> M >> K;
	rep(i, M) {
		cin >> L[i] >> R[i];
		--L[i];
		in[L[i]].pb(i);
		out[R[i]].pb(i);
	}

	dp[0][0] = 1;
	for (int i = 1; i <= K; ++i) {
		pref[0] = 0;
		rep(j, N) {
			pref[j + 1] = (pref[j] + dp[i-1][j]) % MOD;
		}

		ll s = 0;

		for (int j = 0; j <= N; ++j) {
			for (auto t : in[j]) {
				s += (pref[R[t]] - pref[L[t]]) % MOD;
				s %= MOD;
				if (s < 0) s += MOD;
			}
			for (auto t : out[j]) {
				s -= (pref[R[t]] - pref[L[t]]) % MOD;
				s %= MOD;
				if (s < 0) s += MOD;
			}
			dp[i][j] = s;
		}
	}

	cout << dp[K][N-1] << endl;
	return 0;
}