//** ADT STACK – NONMEMBER print characters*/
void printCharacters (string characters){
    int size = (int)characters.length();
    stack <char> evenStack, oddStack;
    string reverse;
    for (int iterator = size; iterator >= 0; iterator--){
        reverse = reverse + characters[iterator];}
    if (size % 2 == 0){
      for (int i = 0; i <= size; i = i+2){
         evenStack.push(reverse[i]); }
      for (int k = 1; k < size; k=k+2){
         oddStack.push(reverse[k]); }
      while(!evenStack.empty()){
        cout << evenStack.top() << " ";
        evenStack.pop();}
        cout << endl;
      while(!oddStack.empty()){
        cout << oddStack.top() << " ";
        oddStack.pop();}
        cout << endl;   
    }
    else {
        cout<<"Amount of characters isn't even."<< endl;
    }
}