subseg fn

#include <bits/stdc++.h>
using namespace std;
//----------------------------------
constexpr int NMAX = 1e5 + 3;
int f[NMAX];
int dp[NMAX];

signed main() {
    int a, b;
    cin >> a >> b;
    int n = 0;
    for (int x, i = 0; i < b - a + 1; i++) {
        cin >> x;
        if (x != f[n]) {
            f[++n] = x;
        }
    }
    dp[1] = dp[2] = 1;
    for (int i = 3; i <= n; i++) {
        bool mono = false;
        mono |= f[i] > f[i - 1] && f[i - 1] > f[i - 2];
        mono |= f[i] < f[i - 1] && f[i - 1] < f[i - 2];
        if (mono) {
            dp[i] = dp[i - 1];
        } else {
            dp[i] = dp[i - 1] + 1;
        }
    }
    cout << dp[n] << endl;
    return 0;
}