l = [] flag = False while flag == False: x = raw_input(' dose tixaio arithmo : ') if x == '!': flag = True else: l.append(float(x)) print l if len(l) % 2 == 0: Case = 'even' else: Case = 'odd' k = [] for i in range(0, len(l) / 2): r = l[i] * l[len(l) - 1 - i] k.append(r) if Case == 'odd': k.append(l[len(l) / 2] ** 2) print k