#include <iostream>
#include <regex>
using namespace std;
 
int main() {
	std::vector<std::string> strings;
	strings.push_back("#");
	strings.push_back("#123");
 
	std::regex rex1("#[0-9]+");
	for (size_t k = 0; k < strings.size(); k++)
	{
		std::cout << "Next string: " << strings[k] << std::endl;
		std::smatch m;
		std::string str = strings[k];
    	if (regex_search(str, m, rex1)) {
			std::cout << "Found: " << m[0] << std::endl;
		}
	}
	return 0;
}

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