#include <bits/stdc++.h>
#include <boost/multi_array.hpp>
#include <boost/optional.hpp>
#include <boost/range/irange.hpp>
#include <boost/range/algorithm.hpp>
#include <boost/range/adaptors.hpp>
//#include <atcoder/all>

//using namespace atcoder;

using namespace std;

namespace adaptor = boost::adaptors;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vl = vector<long>;
using vvl = vector<vl>;
using pii = pair<int, int>;
using pll = pair<long, long>;
using vpii = vector<pii>;
using vpll = vector<pll>;
using vstr = vector<string>;


constexpr ll INF_LL=1LL<<60;
constexpr int INF_I=1LL<<30;

#define rep(i,n) for(int i=0; i<((int)(n)); i++)
#define reps(i,n) for(int i=1; i<=((int)(n)); i++)
#define rrep(i,n) for(int i=((int)(n)); i>0; i--)
#define rreps(i,n) for(int i=((int)(n)-1); i>=0; i--)
#define ALL(x) (x).begin(), (x).end()
#define pb emplace_back

template <typename T>
bool chmax(T &a, const T& b) {
	if (a < b){
		a = b;
		return true;
	}
	return false;
}

template <typename T>
bool chmin(T &a, const T& b) {
	if (a > b){
		a = b;
		return true;
	}
	return false;
}

ll ceilint(ll x, ll y) { //  x/y の 切り上げ
	return (x + y - 1) / y;
}

void Main();

int main() {
	std::cin.tie(nullptr);
	std::ios_base::sync_with_stdio(false);
	std::cout << std::fixed << std::setprecision(15);
	Main();
	return 0;
}

//-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-


void Main() {
	int N,a,b,c;
	cin >> N >> a >> b >> c;
	bool ans = true;
	if ((b <= a && a <= c) || (c <= a && a <= b))
		ans = false;
	cout << (ans ? "Yes" : "No") << endl;
}