String[] addBorder(String[] picture) {
    String[] r = new String[picture.length + 2];
    for(int i = 0;i < picture.length;i++)
        r[i+1] = '*' + picture[i] + '*';
    
    r[picture.length + 1] = r[1].replaceAll(".","*");
    r[0] = r[picture.length + 1];
    return r;
}
