#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

int main(){

    int N, a, b, c;
    cin >> N >> a >> b >> c;

    if (a < b) cout << (a < c ? "Yes" : "No") << endl;
    else cout << (c < a ? "Yes" : "No") << endl;

    return 0;
}