program lab1;
  uses crt;
  var
   ch: char;
   R, Oo: real;
   Ct, A: real;
   P,T: boolean;
  function max_r(a,b:Real):Real;
  begin
   if (a>b) then max_r:=a else max_r:=b;
  end;
  function WrongInput(condition:boolean):boolean;
  begin
   if condition then
   begin
    WriteLn('Wrong input!');
    WrongInput:=false;
   end else WrongInput:=true;
  end;
  begin
   repeat
    clrscr;
    repeat
     writeln('Type radius and center of circle');
     readln(R,Oo);
    until WrongInput((R<0) or (Oo<0));
    repeat
     writeln('Type center of base and lenght of side of triangle');
     readln(Ct,A);
    until WrongInput((Ct<0) or (A<0));
    P:=abs(Oo-Ct)<(R+A/2);
    T:=abs(Oo-Ct)=(R+A/2);
    if P then
     begin
      if (Oo=Ct) then WriteLn('Concentric') else WriteLn('Non Concentric');
      if ((sqrt(sqr(Ct-Oo)+sqr(a*sqrt(3)/2))<=R) or (max_r(Ct+A/2-Oo,Oo-Ct+A/2)<=R)) then WriteLn('Triangle in half-circle')
      else
       if (A/2-abs(Oo-Ct))*sqrt(3)/2>=R then Writeln('Half-Circle in triangle')
       else WriteLn('Crossing');
     end
    else
     begin
      if T then writeln('Touching') else writeln('Not crossing');
     end;
    writeln('Press N/n to exit any other key to restart program');
    ch:=Readkey
   until (ch='N') or (ch='n')
  end.