program assignment3_1;

var pi, r2, x, y:real;
    i, n:longint;

begin

  writeln('How many iterations would you like?');
  readln(n);

  Randomize;

  for i:=1 to n do begin

    x:=Random-0.5;
    y:=Random-0.5;

    if ((sqr(x)+sqr(y))<=0.25) then pi:=pi+1;

  end;

  writeln('Pi = ',(4*pi/n):4:10);

  readln;

end.