#include <bits/stdc++.h>

using namespace std;

ifstream fin("cutii.in");
ofstream fout("cutii.out");

class box {
    public:
        int x, y, z;

        bool operator < (const box &A) const {
            return z < A.z;
        }
};

int N, T;
vector<vector<int>> aib;

void max_self(int &a, int b) {
    a = max(a, b);
}

void update(int x, int y, int val) {
    for(int i = x; i <= N; i += i & -i)
        for(int j = y; j <= N; j += j & -j)
            max_self(aib[i][j], val);
}

int query(int x, int y) {
    int ans = 0;
    for(int i = x; i > 0; i -= i & -i)
        for(int j = y; j > 0; j -= j & -j)
            max_self(ans, aib[i][j]);
    return ans;
}

void test_case() {
    vector<box> a(N);
    for(box &x : a)
        fin >> x.x >> x.y >> x.z;
    sort(a.begin(), a.end());
    aib = vector<vector<int>>(N + 1, vector<int>(N + 1));
    for(const box &x : a) {
        int val = query(x.x, x.y) + 1;
        update(x.x, x.y, val);
    }
    fout << query(N, N) << '\n';
}

int main() {
    fin >> N >> T;
    while(T--)
        test_case();
}