#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
#include <cmath>

using namespace std;

struct Line {
    int x1, y1, x2, y2;
};

int countCells(Line line, pair<int, int> star, bool split) {
    if (line.x1 == line.x2) {
        return split ? min(abs(star.second - line.y1), abs(star.second - line.y2)) + 1 : abs(line.y1 - line.y2) + 1;
    } else {
        return split ? min(abs(star.first - line.x1), abs(star.first - line.x2)) + 1 : abs(line.x1 - line.x2) + 1;
    }
}

bool intersects(Line a, Line b, pair<int, int>& intersection) {
    if (a.x1 == a.x2 && b.y1 == b.y2) {
        if (b.x1 <= a.x1 && a.x1 <= b.x2 && a.y1 <= b.y1 && b.y1 <= a.y2) {
            intersection = {a.x1, b.y1};
            return true;
        }
    } else if (a.y1 == a.y2 && b.x1 == b.x2) {
        if (a.x1 <= b.x1 && b.x1 <= a.x2 && b.y1 <= a.y1 && a.y1 <= b.y2) {
            intersection = {b.x1, a.y1};
            return true;
        }
    }
    return false;
}

int main() {
    int N, K;
    cin >> N;
    vector<Line> lines(N);
    for (int i = 0; i < N; ++i) {
        cin >> lines[i].x1 >> lines[i].y1 >> lines[i].x2 >> lines[i].y2;
        if (lines[i].x1 > lines[i].x2 || (lines[i].x1 == lines[i].x2 && lines[i].y1 > lines[i].y2)) {
            swap(lines[i].x1, lines[i].x2);
            swap(lines[i].y1, lines[i].y2);
        }
    }
    cin >> K;

    map<pair<int, int>, vector<Line>> stars;
    for (int i = 0; i < N; ++i) {
        for (int j = i + 1; j < N; ++j) {
            pair<int, int> intersection;
            if (intersects(lines[i], lines[j], intersection)) {
                stars[intersection].push_back(lines[i]);
                stars[intersection].push_back(lines[j]);
            }
        }
    }

    int totalIntensity = 0;
    for (auto& star : stars) {
        if (star.second.size() / 2 == K) {
            vector<int> intensities;
            for (auto& line : star.second) {
                intensities.push_back(countCells(line, star.first, true));
            }
            totalIntensity += *min_element(intensities.begin(), intensities.end());
        }
    }

    cout << totalIntensity << endl;
    return 0;
}

`

int main() {
    int n;
    scanf("%d", &n);
    int arr[n];
    for (int i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    int count = 0;
    int num = arr[0];

    for (int i = 1; i < n; i++) {
        if (num != arr[i]) {
            count++;
            num = arr[i];
        }
    }

    printf("%d\n", count);
    return 0;
}

int main() {
    int n, m, k, d = 1, rv = 0;
    cin >> n >> m;
    vector<set<int>> f(n);
    for (int i = 0, u, v; i < m; ++i) {
        cin >> u >> v;
        f[u].insert(v);
        f[v].insert(u);
    }
    cin >> k;
    vector<bool> w(n, true);
    rv = n;
    while (rv < k) {
        vector<bool> nw(n, false);
        for (int i = 0; i < n; ++i) {
            int cnt = 0;
            for (int fr : f[i]) cnt += w[fr];
            if (w[i] && cnt == 3) nw[i] = true;
            else if (!w[i] && cnt < 3) nw[i] = true;
        }
        w = nw;
        rv += count(w.begin(), w.end(), true);
        ++d;
    }
    cout << d;
    return 0;
}

#include <iostream>
#include <string>
#include <vector>
#include <unordered_map>

using namespace std;

int f(string& s, vector<string>& v, unordered_map<string, int>& m) {
    if (m.count(s)) return m[s];
    int res = 0;

    for (auto& x : v) {
        size_t p = s.find(x);
        if (p != string::npos) {
            string ns = s.substr(0, p) + s.substr(p + x.size());
            res = max(res, 1 + f(ns, v, m));
        }
    }

    return m[s] = res;
}

int main() {
    int n;
    cin >> n;
    vector<string> subs(n);
    for (int i = 0; i < n; ++i) {
        cin >> subs[i];
    }

    string s;
    cin >> s;

    unordered_map<string, int> m;

    cout << f(s, subs, m) << endl;

    return 0;
}