编译并运行这段代码后，输出结果是什么？(     )

public class Test {
    static int a;
    int b;
    public Test() {
        int a, b, c;
        a = b = c = 20;
        System.out.println(a);
    }
    public static void main(String args[]) {
        new Test();
    }
}