def redact_line(line):
    i = 0
    new_line = ''
    while True:

        if is_phone_num(line[i:i+12]):
            for j in range(i,i+12):
                if line[j] != '-':
                    new_line += 'X'
                    i+=1
                else:
                    new_line += line[j]
                    i+=1
        else:
            new_line += line[i]
            i+=1

        if i == len(line):
            break

    return new_line