import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.Scanner;


public class Question1 {

	public static void main(String[] args) throws Exception {
		BufferedWriter fileout = new BufferedWriter(new FileWriter("OUT1.txt"));
		Scanner scan = new Scanner(new FileReader("DATA1.txt"));
		while (scan.hasNextLine()) {
			String[] coordinates = scan.nextLine().split(" ");
			int x1 = Integer.valueOf(coordinates[0]);
			int y1 = Integer.valueOf(coordinates[1]);
			int x2 = Integer.valueOf(coordinates[2]);
			int y2 = Integer.valueOf(coordinates[3]);
			double slope1 = (double) y1 / (double) x1;
			double atan1 = Math.atan(slope1) + (Math.PI / 2);
			if (x1 < 0) atan1 += Math.PI;
			atan1 = Math.toDegrees(atan1);
			double slope2 = (double) y2 / (double) x2;
			double atan2 = Math.atan(slope2) + (Math.PI / 2);
			if (x2 < 0) atan2 += Math.PI;
			atan2 = Math.toDegrees(atan2);
			double answer = atan1 - atan2;
			if (answer < 0) answer += 360;
			fileout.write(String.valueOf(answer));
			fileout.newLine();
		}
		fileout.close();
	}

}