class Example1
{   int x=1,y=2;

    void a(int x)
    {   int y=20;
        int z1=x;
        int z2=this.x;
        int z3=y;
        int z4=this.y;
        System.out.println("z1="+z1+";z2="+z2);
        System.out.println("z3="+z3+";z4="+z4);
    }
}

public class ExamDemo
{   public static void main(String args[ ])
    {   Example1 e=new Example1( );
        e.a(10);
    }
}