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
#include <bits/stdc++.h>

using namespace std;

int n, m;

void apply(int l, int r, int k, vector< vector<bool> > &row) {
    for(int i = l; i <= r; ++i) {
        row[i][k-1] = true;
    }
}

vector< vector<bool> > readAndApply() {
    int l, r, k;

    cin >> n >> m;
    vector< vector<bool> > row(n, vector<bool> (3, false));

    for(int i = 0; i < m; ++i) {
        cin >> l >> r >> k;
        apply(l, r, k, row);
    }
    return row;
}

int solve(vector< vector<bool> > row) {
    vector<bool> green(2, true);
    green.push_back(false);

    int res = 0;

    for(int i = 0; i < n; ++i) {
        if(row[i] == green)
            res++;
    }

    return res;
}

int main()
{
    cin.tie(0);
    cout.tie(0);
    ios_base::sync_with_stdio(0);
    vector< vector<bool> > row = readAndApply();
    cout << solve(row) << endl;
    return 0;
}