#include <vector> 
#include <iostream> 

int main() 
{ 
  std::vector<char> v; 
  v.push_back('a'); 
  v.push_back('b'); 
  v.push_back('c'); 

  std::cout << v[0] << std::endl; 
  std::cout << v.at(2) << std::endl; 
  std::cout.write(&v[0], v.size()) << std::endl; 
}