请大神帮忙查看下错误在哪里？
In [20]: while a<=50:
    ...:     if a==3:
    ...:        continue
    ...:     print(a)
    ...:      
    ...:      
    ...:  
    ...:      
    ...:  
    ...:  
    ...:  
    ...:         
    ...:                                                                                                                                                                        
^C---------------------------------------------------------------------------
KeyboardInterrupt                         Traceback (most recent call last)
<ipython-input-20-084ffdee89d1> in <module>
      1 while a<=50:
----> 2     if a==3:
      3        continue
      4     print(a)
      5

这个问题，我看了看应该是死循环了下去，这里的a初始化之后还要设定循环的条件和增值。

比如设定while a<=50
              a=a*2.....
              .....