#include <fstream>
#define SMAX 1050000

std::ifstream fin("text.in");
std::ofstream fout("text.out");

int sum, cuv;
char str[SMAX];

inline bool isLetter(char chr) {
    return 'a' <= chr && chr <= 'z' || 'A' <= chr && chr <= 'Z';
}

int main() {

    while (fin.getline(str, SMAX))
        for (int i = 0; str[i]; i++)
            if (isLetter(str[i])) {
                sum++;
                if (!i || !isLetter(str[i - 1]))
                    cuv++;
            }

    fout << sum / cuv << '\n';
    fout.close();
    return 0;
}