#include <bits/stdc++.h>
using namespace std;
int main () {
    int N;
    cin >> N;
    int a, b, c;
    cin >> a >> b >> c;
    if (a == c) {
        cout << "No" << endl;
    } else {
        cout << (((a < b) == (a < c)) ? "Yes" : "No") << endl;
    }
}