#include <vector>
#include <algorithm>
#include <iostream>

using namespace std;

template<typename T>
void print(vector<T> v) {
  for(auto it = v.cbegin(); it!=v.cend(); it++) 
    cout << *it << ", ";
  cout << endl;
}

void prefixMe(string& str) {
  str = "light " + str;
}

int main() {
  vector<string> colors;
  
  colors.push_back("red");
  colors.push_back("green");
  colors.push_back("blue");
  
  print(colors);
  for_each(colors.begin(), colors.end(), prefixMe);
  print(colors);
}