import java.util.Scanner;

public class Exercise2 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String input = scanner.nextLine();
        int counterMaxSequence = 0;
        int counter = 0;
        boolean isSpecialSymbol;

        for (int i = 0; i < input.length(); i++) {
            char symbol = input.charAt(i);

            isSpecialSymbol = (int) symbol >= 33 && (int) symbol <= 45 || (int) symbol >= 58 && (int) symbol <= 64 || (int) symbol >= 91 && (int) symbol <= 96;

            if (isSpecialSymbol) {
                counter++;
            } else {
                if (counter > 0) {
                    if (counterMaxSequence < counter) {
                        counterMaxSequence = counter;

                    }
                    counter = 0;
                }
            }
        }
        System.out.println(counterMaxSequence);
    }
}