#include <stdio.h>
#include <string.h>

int nr_cuvinte;
int lungime;

int isalpha(char c)
{
	if ((c >= 'A') && (c <= 'Z')) return 1;
	if ((c >= 'a') && (c <= 'z')) return 1;
	return 0;
}

int main()
{
	freopen("text.in", "r", stdin);
	freopen("text.out", "w", stdout);
	
	char a, b;
	a = b = ' ';

	while (scanf("%c", &a) != EOF)
	{
		if (isalpha(a))
		{
			++lungime;
			if (!isalpha(b))
				++nr_cuvinte;
		}

		b = a;
	}

	printf("%d", (nr_cuvinte ? (lungime / nr_cuvinte) : 0));
	return 0;
}