import machine

tx = machine.Pin(2, machine.Pin.OUT)
rx = machine.Pin(3, machine.Pin.IN, machine.Pin.PULL_DOWN)

tx.value(0)

timer = machine.Timer(-1)
tx_val = 0
rx_val = 0
step = 0
done = False

def timer_isr(t):
    global step, tx_val, rx_val, done
    
    if step == 0:
        tx.value(1)
        rx_val = 0
    elif 1 <= step <= 8:
        bit_idx = step - 1
        bit = (tx_val >> bit_idx) & 1
        tx.value(1 - bit)
        
        rx_line = rx.value()
        rx_bit = 1 - rx_line
        rx_val |= (rx_bit << bit_idx)
    elif step == 9:
        tx.value(0)
    elif step == 10:
        tx.value(0)
    elif step == 11:
        tx.value(0)
        t.deinit()
        done = True
        return
        
    step += 1

def send_and_receive_char(char):
    global tx_val, step, done
    tx_val = ord(char)
    step = 0
    done = False
    
    timer.init(freq=9600, mode=machine.Timer.PERIODIC, callback=timer_isr)
    
    while not done:
        pass
        
    return chr(rx_val)

while True:
    text = input()
    if not text:
        continue

    output = ""
    for c in text:
        output += send_and_receive_char(c)

    print("Received:", output)