import java.util.Scanner;
import java.util.Arrays;

public class Game_1 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        //Getting the phrase inside an array
        String a = scanner.nextLine();
        a = a.replace(" ", "");
        a = a.replace(".", "a");
        a = a.toLowerCase();
        String[] phrase = a.split("");

        //Getting the asci codes
        int[] asciArray = new int[phrase.length];

        for (int i = 0; i < asciArray.length; i++) {
            asciArray[i] = (int) a.charAt(i);
        }


        //Counting the longest sequence
        int max = 0;
        int sequence = 0;


        for (int i = 0; i < asciArray.length; i++) {
            boolean lampa = true;

            if ((asciArray[i] >= 48 && asciArray[i] <= 57)) {
                lampa = false;
            } else if ((asciArray[i] >= 97 && asciArray[i] <= 122)) {
                lampa = false;
            }

            if (lampa) {
                sequence++;
            } else {
                if (sequence > max) {
                    max = sequence;
                }
                sequence = 0;
            }



        }

        if(sequence>max){
            max = sequence;
        }

        System.out.println(max);


    }
}