Pi=3.14;
r=float(input('20'));
s2=Pi*r*r;
r=r+20;
s1=Pi*r*r;
s=s1-s2;
print('20',s):

#排序
s=[10,2,3,6,5,4,1,7,9,8,0]  
print(s)
s.sort(reverse = True )
print(s)

s=[10,2,3,6,5,4,1,7,9,8,0]
print(s)
s.sort()
print(s)

#计算
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