#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  scanf("%d", &n);
  string s;
  cin >> s;
  string ans;
  int i = 0, j = 1, cnt = 0;
  while (i < s.size() && j < s.size()) {
    if (s[i] == s[j]) {
      cnt++;
      s.erase(s.begin() + j);
    } else {
      ans += s[i];
      ans += s[j];
      i += 2, j += 2;
    }
  }
  if ((n - cnt) & 1) cnt++;
  printf("%d\n", cnt);
  cout << ans << endl;
}
