{ CS 1621 Strings in standard Pascal.  Note how primitive
   and restrictive these seem }
program pstrings(input,output);

const maxS = 20;
type String = packed array[1..maxS] of char;
     { String type declared above.  Packed array allows readln and
       writeln to work on variable as a whole }

procedure backward(S: String; size: integer);
var i: integer;
begin
     for i := size downto 1 do
     begin
         write(S[i]);
     end;
     writeln;
end;

var S1, S2: String;   { Now S1 and S2 must be declared at the same
                        time and of the same physical size.  Thus,
                        we need to keep length variables for both }
     
    i, size1, size2: integer;

begin  { main }

    for i := 1 to maxS do
    begin
        S1[i] := ' ';
        S2[i] := ' ';
    end;

    size1 := 10;
    write('Enter ', size1:1, ' characters: ');
    readln(S1);
    
    write('How long is your name? (up to ', maxS:1, ' chars): ');
    readln(size2);
    write('Enter your name: ');
    readln(S2);

    write(S1:size1, ' backward is '); backward(S1, size1);
    write(S2:size2, ' backward is '); backward(S2, size2);
end.