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#include <cstdio>

#include <iostream>

#include <map>
#include <string>
#include <vector>
#include <queue>
#include <stack>


using namespace std;

// 1 - zolty
// 2 - niebieski
// 3 - czerwony

// zielony = 1 + 2

class Elem;

Elem *tab;

int minIdx = 10000000;
int maxIdx = -1;

class Elem {

public:
    int from, to;
    int idx;
    bool flag[4];

    void addColor(int color, int sa, int sb) {

        stack<int> qa;
        stack<int> qb;
        stack<int> qi;

        qa.push(sa);
        qb.push(sb);
        qi.push(idx);

        while(!qa.empty()) {

            int a = qa.top();
            qa.pop();

            int b = qb.top();
            qb.pop();

            int idx = qi.top();
            qi.pop();

//            cout << a << " " << b << " " << idx << endl;

            // a <= b

            if (tab[idx].from == a && tab[idx].to == b) {
                tab[idx].flag[color] = true;
            } else {

                Elem *left = &tab[2 * idx];
                Elem *right = &tab[2 * idx + 1];

                // from <= a <= b <= to
                int a1 = a;
                int b1 = min(left->to, b);
                if (a1 <= b1) {
                    qa.push(a1);
                    qb.push(b1);
                    qi.push(2*idx);
//                    left->addColor(color, a1, b1);
                }
                int a2 = max(right->from, a);
                int b2 = min(right->to, b);
                if (a2 <= b2) {
                    qa.push(a2);
                    qb.push(b2);
                    qi.push(2*idx+1);
//                    right->addColor(color, a2, b2);
                }

            }
        }

    }

    Elem() {

    }

    void init(int _from, int _to, int _idx) {

        stack<int> sfrom;
        stack<int> sto;
        stack<int> sidx;

        sfrom.push(_from);
        sto.push(_to);
        sidx.push(_idx);

        while(!sfrom.empty()) {

            int from = sfrom.top();
            sfrom.pop();

            int to = sto.top();
            sto.pop();

            int idx = sidx.top();
            sidx.pop();


            tab[idx].from = from;
            tab[idx].to = to;
            tab[idx].idx = idx;
            for (int i = 0; i < 4; i++) {
                tab[idx].flag[i] = false;
            }
            if (from < to) {
                int x = to - from + 1;
                x /= 2;

                sfrom.push(from);
                sto.push(from + x - 1);
                sidx.push(2*idx);

//                tab[2 * idx].init(from, from + x - 1, 2 * idx);

                sfrom.push(from + x);
                sto.push(to);
                sidx.push(2*idx + 1);


//                tab[2 * idx + 1].init(from + x, to, 2 * idx + 1);
            } else {
                minIdx = min(minIdx, idx);
                maxIdx = max(maxIdx, idx);
            }
        }

    }

};

void ole(bool* f, int start) {

    while(start >= 1) {
        for(int i=0; i<4; i++) {
            f[i] |= tab[start].flag[i];
        }
        start /= 2;
    }

}

int main() {

    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n, m;

    scanf("%d %d", &n, &m);
//    cin >> n >> m;

    int x = 1;
    while (x < n) {
        x *= 2;
    }

    tab = new Elem[2*x+1];

    tab[1].init(1, x, 1);

//    cout << "done init" << endl;

    int l, r, k;
    for (int i = 0; i < m; ++i) {
//        cin >> l >> r >> k;
        scanf("%d %d %d", &l, &r, &k);
        tab[1].addColor(k, l, r);
    }

//    cout << "done reading" << endl;

    bool flag[4];
    int res = 0;
    for(int i=minIdx; i<=maxIdx; ++i) {
        for(int i=0; i<4; ++i) {
            flag[i] = false;
        }
        ole(flag, i);
        if(flag[1] && flag[2] &&!flag[3]) {
            res++;
        }

    }

//    cout << res << endl;
    printf("%d\n", res);


}