#include <iostream>
#include <string>
#include <ctime>


int main()
{
        const std::string s = "20160907-05:00:54.123";

        tm t;
        t.tm_year = stoi(s.substr(0, 4));
        t.tm_mon = stoi(s.substr(4, 2));
        t.tm_mon = stoi(s.substr(4, 2));
        t.tm_mday = stoi(s.substr(6, 2));
        t.tm_hour = stoi(s.substr(9, 2));
        t.tm_min = stoi(s.substr(12, 2));
        t.tm_sec = 0;
        double sec = stod(s.substr(15));
        std::cout << mktime(&t) + sec * 1000;

        return 0;
}