#include <bits/stdc++.h>
 
#define rep(i, n)      for (int i = 0; i < (n); i++)
#define repr(i, n)     for (int i = (n) - 1; i >= 0; i--)
#define repe(i, l, r)  for (int i = (l); i < (r); i++)
#define reper(i, l, r) for (int i = (r) - 1; i >= (l); i--)
#define repi(i, l, r)  for (int i = (l); i <= (r); i++)
#define repir(i, l, r) for (int i = (r); i >= (l); i--)
#define range(a) a.begin(), a.end()
void init_io() { std::cin.tie(nullptr); std::ios::sync_with_stdio(false); std::cout << std::fixed << std::setprecision(15); }
 
using namespace std;
using ll = long long;

void chmax(int &x, int y) {
  x = max(x, y);
}

int main() { init_io();
  int N; cin >> N;
  vector<int> A(N); rep(i, N) cin >> A[i];
  vector<int> dp0(N, -1e9);
  vector<int> dp1(N, -1e9);
  dp0[0] = 0;
  dp1[0] = 1;
  for (int i = 0; i + 1 < N; i++) {
    if (A[i] == A[i + 1]) {
      chmax(dp0[i + 1], dp0[i]);
      chmax(dp0[i + 1], dp1[i]);
      chmax(dp1[i + 1], dp0[i] + 1);
      chmax(dp1[i + 1], dp1[i] + 1);
    } else {
      chmax(dp0[i + 1], dp0[i]);
      chmax(dp0[i + 1], dp1[i]);
      chmax(dp1[i + 1], dp0[i] + 1);
    }
  }
  cout << max(dp0[N - 1], dp1[N - 1]) << endl;
}