public class vector{
	double[] data;
	public int size{
		get{return data.Length;}
	}
	public double this[int i]{
		get{return data[i];}
		set{data[i]=value;}
	}
	//constructor
	public vector(int n){data=new double[n];}
	public void print(string s=""){
		System.Console.Write(s);
		for(int i=0;i<size;i++)
			System.Console.Write("{0:f3} ",this[i]);
		System.Console.Write("\n");
	}
	public static vector operator+(vector u, vector v){
		vector r=new vector(u.size);
		for(int i=0;i<u.size;i++)r[i]=u[i]+v[i];
		return r;
	}
	public static vector operator*(double a, vector v){
		vector r=new vector(v.size);
		for(int i=0;i<v.size;i++)r[i]=a*v[i];
		return r;
	}
	public static vector operator*(vector v, double a){
		return a*v;
	}
}