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
63
64
65
66
67
68
69
70
71
72
#include<bits/stdc++.h>
using namespace std;
using LL = long long;
using D = double;
#define f1 first
#define f2 second
#define randint(a, b) uniform_int_distribution<int>{a, b}(gen)
#ifdef LOC
void OUT() {cout << '\n';}
template<class H, class ... T> void OUT(H h, T ... t)
{
	cout << h << ' ';
	OUT(t...);
}
#define P(...) cout << "[" << #__VA_ARGS__ << "] ", OUT(__VA_ARGS__)
#else
#define P(...)
#define OUT(...)
#endif
//mt19937 gen;
struct Interv
{
	int begin, end;
	bool operator<(const Interv & a)
	{
		if(begin != a.begin) return begin < a.begin;
		return end > a.end;
	}
};

vector<int> colors;
vector<Interv> intervals[3];

int main(int, char ** /*args*/)
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int n, m;
	cin >> n >> m;
	colors.resize(n + 1, 0);
	for(int i = 0; i < 3; ++i)
	{
		intervals[i].push_back({999999999, 999999999});
	}
	for(int i = 0; i < m; ++i)
	{
		int a, b, c;
		cin >> a >> b >> c;
		--c;
		intervals[c].push_back({a, b});
	}
	for(int i = 0; i < 3; ++i) sort(intervals[i].begin(), intervals[i].end());
	for(int t = 0; t < 3; ++t)
	{
		int p = 0;
		for(int i = 1; i <= n; ++i)
		{
			while(intervals[t][p].end < i) ++p;
			if(intervals[t][p].begin <= i && i <= intervals[t][p].end)
			{
				colors[i] ^= (1<<t);
			}
		}
	}
	int ans = 0;
	for(int i = 1; i <= n; ++i)
	{
		if(colors[i] == 3) ++ans;
	}
	cout << ans << '\n';
	return 0;
}