import java.util.Arrays;
class AsciiCharSequence implements CharSequence {
    byte[] array;
    public AsciiCharSequence(byte[] arr){
        this.array = arr;
    }

    @Override
    public String toString() {
        StringBuilder str= new StringBuilder();
        for (int i = 0;i<array.length;++i){
            str.append((char)array[i]);
        }
        return str.toString();
    }

    @Override
    public int length() {
        return array.length;
    }

    @Override
    public char charAt(int index) {
        return (char) array[index];
    }

    @Override
    public CharSequence subSequence(int start, int end) {
        byte[] arr = new byte[end-start];
        int count= 0;
        for (int i = start;i<end;++i){
            arr[count] = array[i];
            count+=1;
        }
        return new AsciiCharSequence(arr);
    }
}