#include<bits/stdc++.h>
#define rep(i,n,m) for(int i = (n); i <(m); i++)
#define rrep(i,n,m) for(int i = (n) - 1; i >=(m); i--)
using namespace std;
using ll = long long;

int main()
{
    int n;
    cin >> n;
    vector<int> A(n+1);
    rep(i, 0, n) cin >> A[i+1];
    A[0] = A[1];

    vector<vector<int>> dp(n+1, vector<int> (2, 0));
    dp[0][0] = 0;
    dp[0][1] = 0;
    rep(i, 0, n)
    {
        dp[i+1][0] = max(dp[i][0], dp[i][1]);
        if (A[i] == A[i+1])
            dp[i+1][1] = max(dp[i][0], dp[i][1]) + 1;
        else
            dp[i+1][1] = dp[i][0] + 1;
    }
    cout << max(dp[n][0], dp[n][1]) << endl;
    return 0;
}