#include <bits/stdc++.h>
using namespace std;
const unsigned long long N = 1e5 + 5;
unsigned long long x, n, y;
string s;
void solve() {
  cin >> n;
  cin >> s;
  string ans;
  ans += s[0];
  int j = 0;
  for (int i = 1; i < s.length(); ++i) {
    if (j + 1 & 1) {
      if (s[i] == ans[j]) continue;
    }
    ans += s[i];
    j++;
  }
  if (ans.length() & 1) ans.pop_back();
  cout << (s.length() - ans.length()) << '\n';
  cout << ans << '\n';
}
int main(int argc, char* argv[]) {
  solve();
  return 0;
}
