program lab2;
var 
   num1,num2 : longint; 
   numm	     : longint;
   numn	     : longint;
   numi	     : longint;
   
function posl(a,b,n: longint) : longint;
var
   k,c : longint;
begin  
   if (n > 2) then begin
      for k := 3 to n do begin
	 c := a + b; a := b; b := c;
      end;
   end
   else begin
      if (n = 1) then c := a; if (n = 2) then c := b;
   end;
   posl := c;
end; { posl }

begin		  
   write('a: ');   readln(num1);
   write('b: ');   readln(num2);
   write('n: ');    readln(numn);
   write('m: ');    readln(numm);
   
   if (posl(num1,num2,numn) > 0) then begin
      for numi := 1 to numn do begin
	 if (posl(num1,num2,numi) <= numm) then begin
	    write('a',numi,': '); writeln(posl(num1,num2,numi));
	 end;
      end;
   end
   else begin
      for numi := 1 to numn do begin
	 if (posl(num1,num2,numi) >= numm) then begin
	    write('a',numi,': '); writeln(posl(num1,num2,numi));
	 end;
      end;
   end;
end.