for (int j=0 ; j<J; j++) {
           for (int k=0 ; k<K ; k++) {
        	       ro = dr*k;

        	       vector dS = new vector (0,0,ro*dr*dfi);
                   vector B = new vector (0,0,0);
                   vector bodvKruznici = new vector (R+ro*Math.cos(fi),ro* Math.sin(fi) ,0);

                   if (bodvKruznici.abs() < R) {
                           B.z= (y0*I) / (Math.PI*R*R);
                   }

                   cirkulacia = cirkulacia + dS.scalarprod(B);

                   ro = ro + dr;
           }
           fi = fi + dfi;
       }