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
#include <bits/stdc++.h>
using namespace std;
#define mk make_pair
#define fst first
#define sz(x) x.size()
#define snd second
#define pb push_back
#define VAR(v) #v << " = " << v << " "
#define debug if(0)
#define M_PI 3.14159265358979323846
typedef complex<long double> C;
typedef long long ll;
typedef pair<int, int> ii;
typedef vector<ll> Matrix;
const int maxn = (int)1e6 + 9;
const int INF = (int)1e9 + 7;
int mod = (int)1e9 + 7;
vector<int> add[maxn];
vector<int> sub[maxn];
int n, m;

int main(int argc, char* argv[])
{
    ios::sync_with_stdio(false);
    debug; else cin.tie(NULL), cout.tie(NULL);
    cin>>n>>m;
    for(int i = 0; i < m; i++)
    {
        int l, r, k;
        cin>>l>>r>>k;
        k--;
        add[l].pb(k);
        sub[r].pb(k);
    }
    int occ[3] = {0, 0, 0}, ans = 0;
    for(int i = 1; i <= n; i++)
    {
        for(int k : add[i])
            occ[k]++;
        if(occ[0] && occ[1] && !occ[2])
            ans++;
        for(int k : sub[i])
            occ[k]--;
    }
    cout<<ans<<"\n";
    return 0;
}