View Compilation Error

0_0_18915357_2062\Main.java:1: 错误: 需要class, interface或enum
public static void main(String[] args) {
              ^
0_0_18915357_2062\Main.java:3: 错误: 需要class, interface或enum
		BigInteger a,b;
		^
0_0_18915357_2062\Main.java:4: 错误: 需要class, interface或enum
		while(cin.hasNext()){
		^
0_0_18915357_2062\Main.java:6: 错误: 需要class, interface或enum
			b=cin.nextBigInteger();
			^
0_0_18915357_2062\Main.java:7: 错误: 需要class, interface或enum
			System.out.println(a.add(b));
			^
0_0_18915357_2062\Main.java:8: 错误: 需要class, interface或enum
		}
		^
6 个错误