#include<bits/stdc++.h>

using namespace std;
using ll = long long;
int main(){
    ll N;
    ll a, b, c;
    cin >> N >> a >> b >> c;
    bool ok = true;
    if(a==c){
        ok=false;
    }else if(a>c&&b>a){
        ok = false;
    }else if(a<b&&a>c){
        ok = false;
    }
    if(ok){
        cout << "Yes" << endl;
    }else{
        cout << "No" <<endl;
    }
}