import java.util.Scanner;

public class Principal {

    public static void main(String[] args)
    {
        Scanner s=new Scanner(System.in);

        System.out.println("A: ");
        double a = s.nextDouble();
        System.out.println("Beta: ");
        double beta = s.nextDouble();
        System.out.println("B: ");
        double b = s.nextDouble();

        double resul = beta*2*Math.PI/360;

        double r = Math.sqrt(a*a+2*a*b*Math.cos(resul)+b*b);

        System.out.println(r);
    }

}