{$N+}Program M;

FUNCTION f1(x,y:real):real;
BEGIN
    f1:=(y*y+2*y+1-x*x)/4;
END;

FUNCTION ff1(x,y:real):real;
BEGIN
    ff1:=x*x+4*x-y*y-2*y-1;
END;

FUNCTION f2(x,y:real):real;
BEGIN
    f2:=(4-x*x)/5;
END;

FUNCTION ff2(x,y:real):real;
BEGIN
    ff2:=x*x+5*y-4;
END;

VAR
   n,i:integer;
   xo,yo,xn,yn:real;

BEGIN

n:=1;
xo:=0;
yo:=0;

FOR i:=1 to 20 DO BEGIN
WRITELN('Krok ',n,' (xo,yo) (',xo:6:5,',',yo:6:5,') (f1,f2) (',ff1(xo,yo):6:5,',',ff2(xo,yo):6:5,')');

xn:=f1(xo,yo);
yn:=f2(xo,yo);

xo:=xn;
yo:=yn;

n:=n+1;
readln;

END;

readln;

END.