program Snak3;
uses  Crt;

.....
  c:='1'+c;
 end;
end;

function IntToStr(a: Integer): string;
var  s: string;
begin
  Str(a, s);
  IntToStr := s;
end;

begin
write('Enter n');
......  
...... um(s,IntToStr(k),s);