View Compilation Error

0_0_33023379_21379\Main.java:1: 错误: 需要class, interface或enum
    public static void main(String[] args) {
                  ^
0_0_33023379_21379\Main.java:3: 错误: 需要class, interface或enum
        double sum;
        ^
0_0_33023379_21379\Main.java:4: 错误: 需要class, interface或enum
        while (scanner.hasNext()) {
        ^
0_0_33023379_21379\Main.java:6: 错误: 需要class, interface或enum
            double y1 = scanner.nextDouble();
            ^
0_0_33023379_21379\Main.java:7: 错误: 需要class, interface或enum
            double x2 = scanner.nextDouble();
            ^
0_0_33023379_21379\Main.java:8: 错误: 需要class, interface或enum
            double y2 = scanner.nextDouble();
            ^
0_0_33023379_21379\Main.java:10: 错误: 需要class, interface或enum
            sum=Math.sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));
            ^
0_0_33023379_21379\Main.java:12: 错误: 需要class, interface或enum
            System.out.printf("%.2f\r\n",sum);
            ^
0_0_33023379_21379\Main.java:13: 错误: 需要class, interface或enum
        }
        ^
9 个错误