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#include <bits/stdc++.h>
#define dbg(x) " [" << #x << ", " << (x) << "] "
using namespace std;
template<typename T>
ostream& operator<<(ostream& o, const vector<T>& v) {
    o << "{";
    for(auto it = v.begin(); it != v.end(); it++) {
        if(it != v.begin()) o << ", ";
        o << *it;
    }
    return o << "}";
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    vector<int> v(n);
    for(int& i : v) cin >> i;
    vector<vector<vector<int>>> dp(n, vector<vector<int>>(2, vector<int>(2, 1e9)));
    dp[0][0][0] = 0;
    dp[0][0][1] = 0;
    dp[0][1][0] = 1;
    dp[0][1][1] = 1;
    for(int i = 1; i < n; i++) {
        dp[i][0][0] = dp[i - 1][1][1];
        if(v[i - 1] > v[i]) {
            dp[i][0][0] = min(dp[i][0][0], dp[i - 1][0][1]);
        }
        dp[i][0][1] = dp[i - 1][1][0];
        if(v[i - 1] < v[i]) {
            dp[i][0][1] = min(dp[i][0][1], dp[i - 1][0][0]);
        }
        dp[i][1][0] = 1 + min(dp[i - 1][0][1], dp[i - 1][1][1]);
        dp[i][1][1] = 1 + min(dp[i - 1][0][0], dp[i - 1][1][0]);
    }
    cout << min({dp[n - 1][0][0], dp[n - 1][0][1], dp[n - 1][1][0], dp[n - 1][1][1]}) << endl;
    return 0;
}