1063: 求圆的面积

Memory Limit:128 MB Time Limit:1.000 S
Judge Style:Text Compare Creator:
Submit:48 Solved:16

Description

输入圆的半径,若大于0,则输出圆的面积(保留两位小数);若小于等于0,则输出“不是圆”。(pi3.14

Input

-1

Output

不是圆

Sample Input Copy

1.5

Sample Output Copy

7.07