#include <sstream>
#include <fstream>
#include <iostream>
#include <math.h>


 
using namespace std;

ifstream in ("DATA1.txt");
ofstream out ("OUT1.txt");

int main ()
{
    freopen ("DATA1.txt", "r", stdin);
    freopen ("OUT1.txt", "w", stdout);
  
   for (int ab= 0; ab<5; ab++)
    {
        double a, b, c, d; 
        in >> a;
        in >> b;
        in >> c;
        in >> d;
        double s1, s2, s3; 
        s1 = sqrt (a*a + b*b);
         s2= sqrt (c*c + d*d);
         s3 = sqrt ((d-b)* (d-b) + (c - a) * (c-a));
         double m1, m2;
         double  ac = b/a;
         double ae = d/c;
         m1 = fabs (ac);
         m2 = fabs (ae);
         double ab;
        ab = acos ((s1*s1 + s2*s2 - s3*s3 )/ (2*(s1*s2)));
        ab = ab * 180/3.14159;
        
  
        if (m1 < m2) 
        {
               ab = 360-ab;
         
           }
          
        cout.precision(1);
        
      cout <<   fixed<<  ab;
       
cout << "\n";
        
    }
}