import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;

public class Main {
	public static void main(String[] args) throws IOException {
		BufferedReader in = new BufferedReader(new FileReader("text.in"));
		int i = 0;

		int sum = 0;
		int count = 0;
		int no = 0;

		char prev = 0;
		while ((i = in.read()) != -1) {
			char ch = (char) i;
			if (Character.isLetter(ch)) {
				count++;
			} else {
				if (Character.isLetter(prev)) {
					no++;
					sum += count;
					count = 0;
				}
			}

			prev = ch;
		}
		in.close();

		PrintWriter out = new PrintWriter("text.out");
		out.println(sum / no);
		out.close();
	}
}