#include <vector>
#include <string>
#include <iostream>

int main() {
  std::vector<std::vector<std::string>> database;

  database = {
    { "name", "username" },
    { "john", "unwanted_guest"},
    { "laith", "ducc" }
  };

  for (std::vector entry: database) {
    std::cout << entry[0] << " | " << entry[1] << std::endl;
  }
}