#include <iostream>
#include <cmath>
using namespace std;
struct vec2{
    double x,y;
    vec2(){
        x=0;
        y=0;
    }
    vec2(double x_, double y_){
    x = x_;
    y = y_;
}
    double lengh(){
        return sqrt(x*x+y*y);
    }
    void print(){
        cout<<x<<' '<<y<<endl;
}
    void set_polar(double ph, double r){
        y = r*sin(ph);
        x = r*cos(ph);
    }
};
int main()
{
    vec2 a(2,5),b(1,3);
    /*cout<<a.lengh()<<endl;
    cout<<b.lengh()<<endl;*/

    a.set_polar(0.785,3);
    b.set_polar(0.785,1);
    a.print();
    b.print();
    return 0;
}