uses crt;

procedure data(var a,b,c:real);
var i: byte; ch:char; a1,b1,c1:string; code:integer;
begin
writeln(' Enter  coefficients of equation ');
i:=0;
repeat
  ch := readkey;
  write(ch);
  if (ch=#13) then begin
    inc(i); writeln;
    if i=1 then val(a1,a,code);
    if i=2 then val(b1,b,code);
    if i=3 then val(c1,c,code);
  end
  else begin
    if i=0 then a1:=a1+ch;
    if i=1 then b1:=b1+ch;
    if i=2 then c1:=c1+ch;
  end;
until i=3;
end;