#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
#include <queue>
#include <map>
#include <cmath>
#include <iomanip>
#include <set>
#include <cstdio>
#include <string>

using namespace std;

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(15);
  int n;
  cin >> n;
  int a, b, c;
  cin >> a >> b >> c;
  if (c > b && b > a || a > b && b > c) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
  return 0;
}