1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
#include <set>
#include <map>
#include <array>
#include <random>
#include <cmath>
#include <list>
#include <ctime>
#include <sstream>
#include <queue>
#include <climits>
#include <stack>
#include <random>
#include <bitset>
#include <numeric>
#include <cassert>
using namespace std;
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef long long ll;
#define rep(x, b, e) for(int x=(b); x<(e); ++x)
#define trav(a, x) for(auto& a : x)
#define ford(x, b, e) for(int x=((int)(b))-1; x>=(e); --x)
#define all(c) c.begin(),c.end()
#define sz(x) ((int)((x).size()))
#define pb push_back
#define st first
#define nd second
#define mp(x,y) make_pair(x,y)
typedef short int sint;

#define imie(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0);
	int n, m;
	scanf("%d %d", &n, &m);
	int KOL = 3;
	vector<vector<int>> happ(KOL, vector<int>(n + 1));
	rep(i, 0, m) {
		int l, r, k;
		scanf("%d %d %d", &l, &r, &k);
		--l; --k;
		++happ[k][l];
		--happ[k][r];
	}
	vi curr(KOL);
	int res = 0;
	rep(i, 0, n) {
		rep(kol, 0, KOL) {
			curr[kol] += happ[kol][i];
		}
		if (curr[0] > 0 && curr[1] > 0 && curr[2] == 0) {
			++res;
		}
	}
	printf("%d\n", res);
}