/******************************************************************************

                            Online Java Compiler.
                Code, Compile, Run and Debug java program online.
Write your code in this editor and press "Run" button to execute it.

*******************************************************************************/

public class Main
{
    public static int gcd(int a, int b)
    {
        if(a == 0)
        {
            System.out.println("Строка 15");
            return b;
        }

        if(b == 0)
        {
            System.out.println("Строка 21");
            return a;
        }

        if(a > 0 && b < 0 || a < 0 && b > 0)
        {
            System.out.println("Строка 27");
            b = -b;
        }

        do
        {
            System.out.println("Строка 33");
            if(a == b)
            {
                System.out.println("Строка 36");
                return a;
            }

            if(b > a && a > 0 || b < a && a < 0)
            {
                System.out.println("Строка 42");
                a = b - a;
                b = b - a;
                a = a + b;
            }

            System.out.println("Строка 48");
            b = a - b;
            a = a - b;
        }
        while(b != 0);

        System.out.println("Строка 54");
        return a;
    }
	public static void main(String[] args) {
		System.out.println(gcd(-1, 1));
	}
}