def pretify(phone):
    phone = str(phone)
    if len(phone) == 11:
        phone = '+{0}({1}) {2} {3} {4}'.format(phone[0],phone[1:4],phone[4:7],phone[7:9],phone[9:11]) 
    return phone
    
    
## pretify(f) => '+8(921) 777 99 11'