#include <bits/stdc++.h>
using namespace std;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N;
    cin >> N;
    vector<int> As(N, 0);
    for (auto & a: As) cin >> a;
    vector<int> ans0(N, 0);
    vector<int> ans1(N, 0);
    ans1[0] = 1;
    for (int i = 1; i < N; ++i){
        // previous mochi is zunda.
        if (As[i - 1] == As[i]){
            ans1[i] = ans1[i - 1] + 1;
        }else{
            ans1[i] = ans1[i - 1];
        }
        ans0[i] = ans1[i - 1];
        // previous mochi is not zunda.
        ans1[i] = max(ans1[i], ans0[i - 1] + 1);
        ans0[i] = max(ans0[i], ans0[i - 1]);
    }
    cout << max(ans1[N - 1], ans0[N - 1]) << endl;
    return 0;
}