View Compilation Error

0_0_15436173_12445\Main.java:2: 错误: 非法字符: '#'
#include <stdio.h>
^
0_0_15436173_12445\Main.java:2: 错误: 需要class, interface或enum
#include <stdio.h>
         ^
0_0_15436173_12445\Main.java:8: 错误: 需要class, interface或enum
    while(scanf("%lf",&l)!=EOF)
    ^
0_0_15436173_12445\Main.java:12: 错误: 需要class, interface或enum
        r=1/pi;
        ^
0_0_15436173_12445\Main.java:13: 错误: 需要class, interface或enum
        s=0.5*l*l/pi;
        ^
0_0_15436173_12445\Main.java:14: 错误: 需要class, interface或enum
        printf("%.2lf\n",s);
        ^
0_0_15436173_12445\Main.java:17: 错误: 需要class, interface或enum
    }
    ^
0_0_15436173_12445\Main.java:20: 错误: 需要class, interface或enum
}
^
8 个错误