Challenge 9 (Pascal)

program challenge9;
type TLowAlpha = 'a'..'z';
const LOWALPHA : set of char = ['a'..'z'];
      DIGITS : set of char = ['0'..'9'];
      FILE_NAME = 'challenge9_list.txt';
var alpha : array[TLowAlpha] of byte = (0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0);
    i : TLowAlpha;
    sumdigit : smallint = 0;
    f : text;
    s : string = '';

begin
    assign(f, FILE_NAME);
    reset(f);
    while not eof(f) do begin
        readln(f, s);
        if s[1] in DIGITS then
            inc(sumdigit, ord(s[1]) - ord('0'))
        else if s[1] in LOWALPHA then
            inc(alpha[s[1]]);
    end;
    close(f);
    writeln('Sum = ', sumdigit);
    for i := 'a' to 'z' do
        if alpha[i] <> 0 then
            writeln(i, ' = ', alpha[i]);
    readln;  // pausa
end.