#include <iostream>
#include <fstream>
#include <locale>
#include <cstring>
using namespace std;

#define BUFFER_SIZE 1024

int main() {
	char buffer[BUFFER_SIZE];

	ifstream in("text.in");
	in.getline(buffer, BUFFER_SIZE - 1);

	int word_count = 0;
	int alpha_letter_count = 0;
	bool last_was_alpha = false;
	for (int i = 0; i < strlen(buffer); i++) {
		bool now_is_alpha = isalpha(buffer[i]);
		if (now_is_alpha) {
			alpha_letter_count++;
		}
		if (!last_was_alpha && now_is_alpha) {
			word_count++;
		}
		last_was_alpha = now_is_alpha;
	}

	cout << (alpha_letter_count / word_count) << endl;
}