public class Main {
    public static void main(String[] args) {
        ArrayList<String> list = new ArrayList<String>();
        try {
            File f = new File("input.txt");
            Scanner read = new Scanner(f);
            while (read.hasNextLine()) {
                list.add(read.nextLine());
            }
            read.close();
        } catch (FileNotFoundException e) {
            System.out.println("An error occurred.");
            e.printStackTrace();
        }

        System.out.println(list);

        int initialPos = 0;
        int finalPos = 0;
        String s = "";
        ArrayList<String> wordList = new ArrayList();

        for (int i = initialPos; i < list.size(); i++) {
            if (list.get(i).isBlank()) {
                finalPos = i;
                for (int j = initialPos; j < finalPos; j++) {
                    s = s + list.get(j);
                }
                String[] words = s.split(" ");
                Collections.addAll(wordList, words);
                s = "";
                initialPos = finalPos;
            }
        }
        System.out.println(wordList);
        String a = "a";
        String b = "b";
        String c = "c";
        String d = "d";
        String e = "e";
        String f = "f";
        String g = "g";
        String h = "h";
        String i1 = "i";
        String j = "j";
        String k = "k";
        String l = "l";
        String m = "m";
        String n = "n";
        String o = "o";
        String p = "p";
        String q = "q";
        String r = "r";
        String s1 = "s";
        String t = "t";
        String u = "u";
        String v = "v";
        String w = "w";
        String x = "x";
        String y = "y";
        String z = "z";
        int count = 0;
        for (String value : wordList) {
            if (value.contains(a)) {
                count++;
            }
            if (value.contains(b)) {
                count++;
            }
            if (value.contains(c)) {
                count++;
            }
            if (value.contains(d)) {
                count++;
            }
            if (value.contains(e)) {
                count++;
            }
            if (value.contains(f)) {
                count++;
            }
            if (value.contains(g)) {
                count++;
            }
            if (value.contains(h)) {
                count++;
            }
            if (value.contains(i1)) {
                count++;
            }
            if (value.contains(j)) {
                count++;
            }
            if (value.contains(k)) {
                count++;
            }
            if (value.contains(l)) {
                count++;
            }
            if (value.contains(m)) {
                count++;
            }
            if (value.contains(n)) {
                count++;
            }
            if (value.contains(o)) {
                count++;
            }
            if (value.contains(p)) {
                count++;
            }
            if (value.contains(q)) {
                count++;
            }
            if (value.contains(r)) {
                count++;
            }
            if (value.contains(s1)) {
                count++;
            }
            if (value.contains(t)) {
                count++;
            }
            if (value.contains(u)) {
                count++;
            }
            if (value.contains(v)) {
                count++;
            }
            if (value.contains(w)) {
                count++;
            }
            if (value.contains(x)) {
                count++;
            }
            if (value.contains(y)) {
                count++;
            }
            if (value.contains(z)) {
                count++;
            }
        }
        System.out.println(count);
    }
}