BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); FileInputStream fileInputStream = new FileInputStream(reader.readLine()); Map <Integer,Integer> map = new HashMap<>(); int count =0; while (fileInputStream.available()>0){ int temp = fileInputStream.read(); if (!map.containsKey(temp)){ map.put(temp,count); }else { map.replace(temp,count+1); } } int max = 0; for (Map.Entry<Integer,Integer> repeat : map.entrySet()){ System.out.print(repeat.getKey()+" "); if (repeat.getValue()>=max) max=repeat.getValue(); reader.close(); } fileInputStream.close();