View Compilation Error

0_0_13443958_31902\Main.java:1: 错误: 需要class, interface或enum
public static void main(String[] args)
              ^
0_0_13443958_31902\Main.java:4: 错误: 需要class, interface或enum
   while(scanf("%lf %lf %lf %lf",&x1,&y1,&x2,&y2)!=EOF) //!=EOF是搞acm的特色，也可以用~来表示，如  while(~scanf("%lf %lf %lf %lf",&x1,&y1,&x2,&y2))
   ^
0_0_13443958_31902\Main.java:7: 错误: 需要class, interface或enum
   } 
   ^
0_0_13443958_31902\Main.java:9: 错误: 需要class, interface或enum
}
^
4 个错误