Що не так?
package com.javarush.task.task18.task1803;
import javax.swing.text.html.HTMLDocument;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.*;
/*
Самые частые байты
*/
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
FileInputStream fileInputStream = new FileInputStream(reader.readLine());
Map<Integer, Integer> map = new HashMap<>();
while (fileInputStream.available() > 0) {
int r = fileInputStream.read();
map.merge(r, 1, (k, v) -> k + v);
}
int max = Collections.max(map.values());
map.entrySet().stream().filter(x->x.getValue() == max).forEach(x-> System.out.print(x.getKey()+" "));
reader.close();
fileInputStream.close();
}
}