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


using namespace std;

double calc ( double a ,  double b,  double c, double d)
{
       double sidea, sideb, sidec, angle,slopea,slopeb;
       sidea = sqrt((a*a)+(b*b));
       sideb = sqrt((c*c)+(d*d));
       sidec = sqrt( ((d-b)*(d-b))+((c-a)*(c-a)) );
       angle = acos(((sidea*sidea)+(sideb*sideb)-(sidec*sidec))/(2*sidea*sideb));
       angle = angle /3.1415926535*180;
       if (a == 0)
       {
             if (b>0)
             {
             slopea = - 999999;}
             if (b<0)
             {
             slopea = 999999;}
             }
        else
        {slopea = b/a;}
        
       if (c == 0)
       {if (d>0)
        {
             slopeb = - 999999;}
        if (d<0)
        {
             slopeb = 999999;}
             }
        else
        {slopeb = d/c;}

       if (slopea < slopeb)
       {angle = 360- angle;}
       return angle;
}
int main()
{
    int coor[20];
    int i;
    char *outname = "OUT1.txt";
    ofstream outfile(outname);
    char *inname = "DATA1.txt";
    ifstream infile(inname);
     for(int icount = 0; icount<20; icount++)  
            {
            coor[icount] = 0;
            } 
    for(int icount = 0; icount<20; icount++)
            {
            infile >> coor[icount];
            }
    outfile.precision(1);
    outfile << fixed << calc( coor[0],coor[1],coor[2],coor[3])<<endl;
    outfile << fixed<< calc( coor[4],coor[5],coor[6],coor[7])<<endl;
    outfile << fixed<< calc( coor[8],coor[9],coor[10],coor[11])<<endl;
    outfile << fixed<< calc( coor[12],coor[13],coor[14],coor[15])<<endl;
    outfile << fixed<< calc( coor[16],coor[17],coor[18],coor[19])<<endl; 
    return 0;
}