#include <vector>
#include <algorithm>
#include <functional>
#include <iostream>

bool is_negative(const int& a, const int& b) {
    return a < 0;
}

int main() {
    std::vector<int> vec = {-1, -2, -3, 4, 5};
    auto Mf = std::bind(is_negative, std::placeholders::_1, 0);
    auto result = count_if(vec.begin(), vec.end(), Mf);
    std::cout << result <<  "\n";
    return 0;
}