#include <iostream>
#include <vector>
using namespace std;

void print(const vector<int> &);

void incr(vector<int> & v, int n=1)
{
  for ( int & val : v )
  {
    val += n;
  }

}

int main()
{
  vector<int> v1 {1,7,3};
  print(v1);
  incr(v1);
  print(v1);
  return 0;
}

void print(const vector<int>  & v)
{
  for ( int a : v )
  {
    cout << a << endl;
  }
}