#include <bits/stdc++.h>

using namespace std;

int main() {
    //cin读入优化
    std::ios::sync_with_stdio(false);
    //输入+输出重定向
    freopen("../1294.txt", "r", stdin);

    int x1, y1, x2, y2;
    cin >> x1 >> y1 >> x2 >> y2;

    if (x1 + 2 == x2 && y1 + 2 == y2) cout << "Yes" << endl;
    else if (x1 - 2 == x2 && y1 - 2 == y2) cout << "Yes" << endl;
    else if (x1 + 2 == x2 && y1 - 2 == y2) cout << "Yes" << endl;
    else if (x1 - 2 == x2 && y1 + 2 == y2) cout << "Yes" << endl;
    else cout << "No" << endl;

    //关闭文件
    fclose(stdin);
    return 0;
}