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

int n;
int t[50007];
int dp[50007][4];

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin >> n;
    for(int i = 1; i <= n; i++){
        cin >> t[i];
    }

    dp[1][0] = 0;
    dp[1][1] = 0;
    dp[1][2] = 1;
    dp[1][3] = 1;
    for(int i = 2; i <= n; i++){\
        if(t[i] < t[i - 1])
            dp[i][0] = min(dp[i-1][1], dp[i-1][3]);
        else
            dp[i][0] = dp[i-1][3];

        if(t[i] > t[i-1])
            dp[i][1] = min(dp[i-1][0], dp[i-1][2]);
        else
            dp[i][1] = dp[i-1][2];
        dp[i][2] = min(dp[i-1][1], dp[i-1][3]) +1;
        dp[i][3] =  min(dp[i-1][0], dp[i-1][2]) +1;

        // cout << dp[i][0] << ' ' << dp[i][1] << ' ' << dp[i][2] << ' ' << dp[i][3] << '\n';
    }
    cout << min(min(dp[n][0], dp[n][1]), min(dp[n][2], dp[n][3]));

return 0;
}