#include <bits/stdc++.h>
using namespace std;

int main() {
    int N,a,b,c;
    cin >> N >> a >> b >> c;
    if(a-1 == c) {
        cout << "Yes" << endl;
    }
    else if(a == 1 && c == N) {
        cout << "Yes" << endl;
    }
    else if(a+1 == c) {
        cout << "Yes" << endl;
    }
    else if(a == N && c == 1) {
        cout << "Yes" << endl;
    }
    else {
        cout << "No" << endl;
    }
}