#include<iostream>
#include<vector>
#include<algorithm>
#include<cmath>
#include<string>
#include<iomanip>
#include<numeric>
#include<queue>
#include<deque>
#include<stack>
#include<set>
#include<map>
using namespace std;
typedef long long ll;
const int mod=1e9+7;
int main(){
	int n,a,b,c;
	cin>>n>>a>>b>>c;
	cout<<(a<b&&a<c||a>b&&a>c?"Yes":"No")<<endl;
}