#include <bits/stdc++.h>
using namespace std;
int n, m;
char s[200010], ss[200010];
int main() {
  scanf("%d%s", &n, s);
  for (int i = 0; i < n; i += 2) {
    while (i + 1 < n && s[i] == s[i + 1]) i++;
    if (i + 1 < n) ss[m++] = s[i], ss[m++] = s[i + 1];
  }
  printf("%d\n", n - m);
  puts(ss);
}
