#include <cstdio>
#include <cctype>

using namespace std;



int main(int argc, char const *argv[])
{

	freopen("text.in", "r", stdin);
	freopen("text.out", "w", stdout);

	char c;
	long long totalLen = 0, wordLen = 0, nWords = 0;

	while ( (c = getchar()) != EOF ) {
		if (isalpha(c)) {
			if (wordLen == 0)
				nWords++;
			wordLen++;
		} else {
			totalLen += wordLen;
			wordLen = 0;
		}
	}

	if (wordLen != 0) {
		totalLen += wordLen;
	}

	printf("%lld\n", nWords == 0 ? 0 : totalLen/nWords);

	return 0;
}