program lab3;
var x, y, U:real;
begin
  writeln(' x', ' y', ' U');
  x:=-1;
  repeat
    y:=-1;
  repeat
    if (x-y<=-1) then
      U:=y*exp(x)
    else if (-1<x-y) and(x-y<1) then
      U:=ln(x*x*x*x+1)
    else U:=x*x-y;
    writeln(x:5:2, ' ', y:5:2, ' ', U:5:3, ' ');
    y:=y+0.2;
    until y>0;
  x:=x+0.4;
  until x>1;
end.