#include <bits/stdc++.h>
#include <atcoder/modint>
using namespace std;
using ll = long long;
using mint = atcoder::modint1000000007;
using vi = vector<int>;

#define rep1(a)          for(ll i = 0; i < ll(a); i++)
#define rep2(i, a)       for(ll i = 0; i < ll(a); i++)
#define rep3(i, a, b)    for(ll i = ll(a); i < ll(b); i++)
#define rep4(i, a, b, c) for(ll i = ll(a); i < ll(b); i += ll(c))
#define overload4(a, b, c, d, e, ...) e
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define all(x)  begin(x),end(x)
#define rall(x) rbegin(x),rend(x)

int main() {
	std::ios_base::sync_with_stdio(false);
	std::cin.tie(nullptr);
	int N, M, K;
	cin >> N >> M >> K;
	vector<pair<int, int>> I(M);
	rep(i, M) {
		int l, r;
		cin >> l >> r;
		I[i] = {--l, r};
	}
	vector<mint> dp(N + 1);
	dp[0] = 1;
	rep(i, K) {
		vector<mint> ndp(N + 1);
		vector<mint> pref(N + 2);
		rep(j, N + 1) pref[j + 1] = pref[j] + dp[j];
		rep(j, M) {
			const auto&[l, r] = I[j];
			mint sum = pref[r] - pref[l];
			ndp[l] += sum;
			ndp[r] -= sum;
		}
		rep(j, 1, N + 1) ndp[j] += ndp[j - 1];
		swap(dp, ndp);
	}
	mint ans = dp[N - 1];
	cout << ans.val( ) << endl;
}