Python 数值计算

print "Welcome to run"
 print "Please input num"
 print "1 stand for 矩形"
 print "2 stand for 圆"
 print "3 stand for 正方形"
 s=int(input("Please input U num:"))
 if s == 1:
     print "input 长度:"
     print "input 宽度:"
     a=int(input("长度:"))
     b=int(input("宽度:"))
     x=a*b
     print x
 elif s == 3:
     print "input 正方形边长"
     v=int(input("边长:"))
     z=v*v
     print v
 elif s == 2:
     print "input 值:"
     c=int(input("半径:"))
     d=c*c*3.14
     print d
 else:
     print "OH no! Please input 1-3"