Не понимаю почему компиляцию не проходит.

String s = Integer.parseInt(reader.readLine());
String n = Integer.parseInt(reader.readLine());

package com.javarush.task.task05.task0532;


import java.io.*;
import java.util.ArrayList;
import java.util.Arrays;

/* 
Задача по алгоритмам
*/

public class Solution {
    public static void main(String[] args) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        int maximum = 0;

        ArrayList<Integer> list = new ArrayList<Integer>();
        
        while (true){
        String s = reader.readLine();
        if (s.isEmpty()) break;
        list.add(Integer.parseInt(s));
        }
        
        for(int i=0; i<list.size(); i++){
            if(list.get(i)>maximum){
                maximum = list.get(i);
                
            }
        }
        System.out.println(maximum);
        
    }
}

while (true){
    String s = reader.readLine();
    if (s.isEmpty()) break;

while (true)

public class Solution {
    public static void main(String[] args) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        int maximum = 0;

        String s = reader.readLine();
        int n = Integer.parseInt(s);

        for(int i=0; i<n; i++){
            String s1 = reader.readLine();
            int n1 = Integer.parseInt(s);

            if(n1>maximum){
                maximum = n1;
            }else{
                continue;
            }
        }

        System.out.println(maximum);
    }
}

package com.javarush.task.task05.task0532;


import java.io.*;
import java.util.ArrayList;
import java.util.Arrays;

/*
Задача по алгоритмам
*/

public class Solution {
    public static void main(String[] args) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));


        String s = reader.readLine();
        int n = Integer.parseInt(s);
        int maximum = n;
        if(n>0){
            for(int i=0; i<n; i++){
            String s1 = reader.readLine();
            int n1 = Integer.parseInt(s1);

            if(n1>maximum){
            maximum = n1;
                }
            }
        }else if(n<=0){
        }
        System.out.println(maximum);
    }
}

else if(n<=0){
}