#include <iostream>

#include <vector>

#include <algorithm>

using namespace std;

​

int main() {

  vector<string> cars = {"Volvo", "BMW", "Ford", "Ford", "Mazda"};

  auto it = adjacent_find(cars.begin(), cars.end());

​

  if (it != cars.end()) {

    cout << *it << " appears twice in a row\n";

  } else {

    cout << "There are no adjacent elements\n";

  }

  return 0;

}

​