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

typedef long long ll;
typedef pair<int,int> P;

#define p_ary(ary,a,b) do { cout << "["; for (int count = (a);count < (b);++count) cout << ary[count] << ((b)-1 == count ? "" : ", "); cout << "]\n"; } while(0)
#define p_map(map,it) do {cout << "{";for (auto (it) = map.begin();;++(it)) {if ((it) == map.end()) {cout << "}\n";break;}else cout << "" << (it)->first << "=>" << (it)->second << ", ";}}while(0)

int main() {
    int n;
    cin >> n;
    vector<int> a(n);
    for (int i = 0;i < n;++i) cin >> a[i];
    vector<int> dp0(n,0),dp1(n,0);
    dp1[0] = 1;
    for (int i = 1;i < n;++i) {
        if (a[i] == a[i-1]) {
            dp1[i] = max(dp1[i-1]+1,dp0[i-1]+1);
            dp0[i] = max(dp1[i-1],dp0[i-1]);
        } else {
            dp1[i] = dp0[i-1]+1;
            dp0[i] = max(dp1[i-1],dp0[i-1]);
        }
    }
    cout << max(dp1[n-1],dp0[n-1]) << endl;
    // p_ary(dp0,0,n);
    // p_ary(dp1,0,n);
    return 0;
}