#include <iostream>
#include <string>
#include <regex>

static std::string get_next_filename(std::string filename)
{
	std::regex
		numbered_reg("(.[^.]*)[(]([1-9][0-9]{0,8})[)](([.].*)?)"),
		unnumbered_reg("(.[^.]*)(([.].*)?)");
	std::smatch what;
	std::string base_name, number, rest;
	long new_idx;

	if (regex_match(filename, what, numbered_reg)) {
		base_name = what[1];
		number = what[2];
		rest = what[3];
		new_idx = std::stol(number) + 1;
	} else {
		regex_match(filename, what, unnumbered_reg);
		base_name = what[1];
		rest = what[2];
		new_idx = 1;
	}
	std:: cout << filename << "  ";
	return base_name + "(" + std::to_string(new_idx) + ")" + rest;
}

int main()
{
	std::cout << get_next_filename("dupa(1)") << std::endl;
	std::cout << get_next_filename("dupa(1).txt") << std::endl;
	std::cout << get_next_filename("....dupa(1).txt") << std::endl;
	std::cout << get_next_filename("dupa(01).kupa(22).png") << std::endl;
	std::cout << get_next_filename("dupa(1)e..txt") << std::endl;
	std::cout << get_next_filename("dupa(111111111).txt") << std::endl;
	std::cout << get_next_filename("dupa(1111111111).txt") << std::endl;
	std::cout << get_next_filename("dupa.txt") << std::endl;
	return 0;
}