#!/usr/bin/python

# encoding=utf-8

# -*- coding: UTF-8 -*-

# 输入三个整数x,y,z，请把这三个数由小到大输出。

l = []

l.append(int(input("first num:\n")))

l.append(int(input("second num:\n")))

l.append(int(input("third num:\n")))

"""

l[0] = int(input("first num:\n"))

l[1] = int(input("second num:\n"))

l[2] = int(input("third num:\n"))

"""

if l[0] > l[1]:

    l[0],l[1] = l[1],l[0]

    if l[1] > l[2]:

        l[1],l[2] = l[2],l[1]

        if l[0] > l[2]:

            l[0],l[2] = l[2],l[0]

for i in range(len(l)):

    print(l[i],end = " ")

    if i == len(l)-1:

        break

    else:

        print("",end = " < ")
    

C:\Python30_demo>python 020demo.py

first num:

6

second num:

4

third num:

5

4  < 5  < 6