#include <iostream>
#include <cmath>
#include <vector>
#include <algorithm>
#include <fstream>

int rank(long hash) {
    int r = 1;
    while((hash & 1) == 0 && r <=32) {
        ++r;
        hash >>= 1;
    }
    return r;
}

std::pair<uint32_t, uint32_t> get_hashes(const std::string &id, std::hash<std::string> hash) {
    uint32_t mask_left = static_cast<uint32_t>(((1 << 16) - 1) << 16);
    uint32_t mask_right = (1 << 16) - 1;
    uint32_t buf = static_cast<uint32_t>(hash(id));
    return std::make_pair(((buf & mask_left) >> 16), buf & mask_right);
}

uint32_t count(std::vector<int> &M) {
    uint32_t m = static_cast<uint32_t>(std::pow(2, 16));
    double alpha = 0.7213 / (1 + (1.079 / m));

    double E = 0;
    for(size_t i = 0; i < M.size(); i++) {
        E += std::pow(2, M[i]);
    }
    E = alpha * m * m * std::pow(E, -1);


    double buf1 = m * 5.0 / 2;
    double buf2 = std::pow(2, 32) / 30.0;

    if (E <= buf1) {
        double zero_count = 0;
        for (size_t i = 0; i < M.size(); i++) {
            if (M[i] == 0) {
                zero_count++;
            }
        }
        if (zero_count != 0) {
            E = m * log(m / zero_count);
        }
    } else if (E > buf2) {
        E = -std::pow(2, 32) * log(1 - (E / std::pow(2, 32)));
    }

    return uint32_t(E);
}

int main() {
    std::string line;
    std::hash<std::string> hash;
    std::vector<int> M(static_cast<int>(std::pow(2, 16)), 0);
//    std::ifstream in("input.txt");
    while (std::cin >> line)
    {
        M[get_hashes(line, hash).first] = std::max(M[get_hashes(line, hash).first], __builtin_ffs(get_hashes(line, hash).second));
    }
    uint32_t unique = count(M);
    std::cout << unique << std::endl;
    return 0;
}