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"