#include <bits/stdc++.h>
using namespace std;
long long power(long long x, long long y, long long p);
int Bit(long long x);
long long sum(long long x);
void Fast() {
  std::ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
}
inline int D() {
  int t;
  scanf("%d", &t);
  return t;
}
inline long long llD() {
  long long t;
  scanf("%lld", &t);
  return t;
}
long long MOD = 1e9 + 7;
const int N = 2e5 + 2;
char arr[N];
int visit[N];
long long cnt;
vector<int> vec;
void seive() {
  for (int i = 2; i < N; ++i) {
    if (visit[i]) continue;
    vec.push_back(i);
    for (long long j = 1ll * i * i; j < N; j += i) visit[j] = true;
  }
}
string str = "";
int main() {
  int n = D();
  scanf("%s", arr);
  str += arr[0];
  for (int i = 1; arr[i]; ++i)
    if (arr[i] != str.back() || !(str.length() & 1)) str += arr[i];
  int x = str.length();
  if (str.length() & 1) str[str.length() - 1] = '\0', --x;
  printf("%d\n%s", n - x, str.c_str());
}
long long power(long long x, long long y, long long p) {
  long long res = 1;
  x = x % p;
  while (y > 0) {
    if (y & 1) res = (res * x) % p;
    y = y >> 1;
    x = (x * x) % p;
  }
  return res;
}
int Bit(long long x) {
  if (!x) return 0;
  return 1 + Bit(x >> 1);
}
long long sum(long long x) { return x * (x + 1) / 2; }
