#include <iostream>
#include <regex>
#include <string>
 
int main(int argc, char *argv[]) {
    std::regex base_regex("[A-Za-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\\.[A-Za-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?\\.)+[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?");
 
    for (const auto& s : {"email@subdomain.domain.com",
					     "Invalid email@subdomain.domain.com",
                         "a@c.c.c.ccb.c",
                         "a@c.c.cc.ccb.c",
                         "a@c.cc.c.ccb.c",
                         "a@cc.c.c.ccb.c"
    })
    {
        std::cout << s << " : " << (std::regex_match(s, base_regex) ? "Found" : "Not found") << std::endl;
    }
 
}

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