int N, count = 0;
  cout << "Количество чисел" << endl;
  cin >> N;

int arr[N];
      cout << "Введите числа" << endl;
   for (int i = 0; i < N; i++)
      cin >> arr[i];
   for (int i = 0; i < N -1 ; i++)
 if (arr[i] < 0 && arr[i+1] >= 0 || arr[i] >= 0 && arr[i+1] < 0)

 count++;
 cout << count << endl;

template<class InputIterator>
typename std::iterator_traits<InputIterator>::difference_type
count_sign_reversals(InputIterator first, InputIterator last) {
  typename std::iterator_traits<InputIterator>::difference_type count = 0;
  if (first == last)
    return count;
  bool sign = *first++ < 0;
  for ( ; first != last; ++first)
    if (sign != (*first < 0)) {
      sign = !sign;
      ++count;
    }
  return count;
}

int main() {
  std::istream_iterator<int> numbers(std::cin), eof;
  std::cout << count_sign_reversals(numbers, eof) << std::endl;
}

#include <algorithm>
#include <iostream>
#include <iterator>

int main()
{
  std::istream_iterator<int> numbers(std::cin), eof;
  decltype(std::distance(numbers, eof)) count = 0;
  if (numbers != eof) {
    count = count_if(numbers, eof, [](int n) {
        static bool sign = n < 0;
        bool changed_sign = (sign != (n < 0));
        if (changed_sign) sign = !sign;
        return changed_sign;
      });
  }
  std::cout << count << std::endl;
}