#include <bits/stdc++.h>
using namespace std;
long long n, a[200000], c = 0;
string s;
int main() {
  cin >> n >> s;
  for (int i = 0; i < n; i += 2) {
    if (s[i] == s[i + 1]) {
      c++;
      a[i--]++;
    }
  }
  if ((n - c) % 2 != 0) {
    a[n - 1]++;
    c++;
  }
  cout << c << endl;
  for (int i = 0; i < n; i++) {
    if (a[i] == 0) cout << s[i];
  }
}
