import?java.util.*;

public?class?MatrixTest{
	int?a[][]={{123}{456}{789}};
	int?b[][]={{111213}{141516}{171819}};
	Matrix?ma?=?new?Matrix（3a）;
	Matrix?mb?=?new?Matrix（3b）;
	public?MatrixTest（）{
System.out.println（“Matrix?a?:“）;
		show（ma）;
System.out.println（“Matrix?b?:“）;
		show（mb）;
System.out.println（“a?add?b?:“）;
		show（ma.add（mb））;
System.out.println（“a?sub?b?:“）;
		show（ma.sub（mb））;
System.out.println（“a?change??:“）;
		show（ma.change（））;
	}


	
	private?void?show（Matrix?ma）{
		for（int?i=0;i			for（int?j=0;j			System.out.print（“??“+ma.getValue（）[i][j]）;
			}
		System.out.println（）;
		}	
	}
	
	public?static?void?main（String?ards[]）{
		new?MatrixTest（）;
		System.out.println（“???ok!“）;
	}
}

class?Matrix{
	private?int?n;
	?int?[][]?value;
	
	public?void?setN（int?n）{
		this.n=n;
	}

	public?int?getN（）{
		return?n;
	}
	
	public?void?setValue（int?xint?yint?z）{
		this.value[x][y]=z;
	}

	public?int[][]?getValue（）{
		return?value;
	}

	public?Matrix?（）{

	}