#include <iostream>
#include <utility>
#include <vector>

int main() {
	
    using LetterNumber = std::pair<char, int>;
    std::vector<LetterNumber> v;
    
    v.push_back( std::make_pair('a',2) );
    v.push_back( std::make_pair('b',3) );
    v.push_back( std::make_pair('c',4) );
    
    for( const auto& e : v )
    {
        std::cout << e.first << " : " << e.second << std::endl;
    }

	return 0;
}