#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, i, t, m;
  string s, s1 = "";
  cin >> n >> s;
  for (i = 0; i < n - 1; i++) {
    if (s[i] != s[i + 1]) {
      s1 += s[i];
      s1 += s[i + 1];
      i++;
    }
  }
  if (s1.size() % 2 == 0) {
    cout << s.size() - s1.size() << '\n' << s1 << '\n';
  } else {
    long long x = s1.size() - 1;
    s1.erase(x, x);
    cout << s.size() - s1.size() << '\n' << s1 << '\n';
  }
}
