Не вижу ошибки, ткините носом, что не так.

public static void main(String[] args) {
        String s = "15";
        a = 5;
        int z = 18;
        int d = 18;
        c = a + d;
        b = " is better than ";

        System.out.println(a + b + c);
    }

package com.javarush.task.task01.task0125;

/*
Большая чистка
*/

public class Solution {
    public static void main(String[] args) {
        // String s = "15";
        int a = 5;
        // int z = 18;
        int d = 18;
        int c = a + d;
        String b = " better than ";

        System.out.println(a + b + c);
    }
}