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#include <stdio.h>
#include <time.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <map> 
#include <string>
#include <vector>  
#include <iostream> 
#include <sstream> 
#include <queue>
#include <algorithm>
#include <assert.h>


using namespace std;

#define ll long long
#define PB 		push_back
#define FOR(a,start,end) 	for(int a=int(start); a<int(end); a++)
#define INF 		INT_MAX
#define SORT(a) 	sort(a.begin(),a.end()) 
#define CL(a,x) 		memset(a,x,sizeof(a))
#define REP(a,x)	for(int a=0;a<x;a++)
#define REP1(a,x)	for(int a=1;a<=x;a++)
#define MP 		make_pair



typedef vector<ll>     vi;
typedef pair<ll, ll>     pii;
typedef vector<string> vs;
typedef vector<pii> vii;
typedef vector<vector<ll> > vvi;
typedef vector<vector<string> > vvs;
typedef vector<pair<string, string> > vss;
typedef pair<string, string> pss;
typedef pair<ll, pii> ppii;
typedef vector<ppii> vppii;
typedef vector<vector<pii> > vvii;
typedef vector<vvi> vvvi;


ll n, k, a, b, m;
vi vk, va, vb;
int td[2000010];

void modify(int l, int r, int value) {
	for (l += n, r += n; l < r; l >>= 1, r >>= 1) {
		if (l & 1) td[l++] |= value;
		if (r & 1) td[--r] |= value;
	}
}
void push() {
	for (int i = 1; i < n; ++i) {
		td[i << 1] |= td[i];
		td[i << 1 | 1] |= td[i];
		td[i] = 0;
	}
}

int main() {
	//freopen("c:\\wojtek\\uva\\pa\\debug\\t1.in", "rt", stdin);

	//pi=2*acos(0.0);
	
	
	cin >> n >> m;

	memset(td, 0, 2000010*sizeof(int));
	for (int i = 0; i < m; i++) {
		cin >> a >> b >> k;
		if (k == 3)
			k++;
		modify(a-1, b, k);
	}
	push();
	k = 0;
	for (int i = n; i < 2 * n; i++) {
		if (td[i] == 3)
			k++;
	}
	cout << k << endl;
	return 0;

}