#include <bits/stdc++.h>

#define F first
#define S second

using namespace std;
using ll = long long;
using pi = pair<int, int>;
using vi = vector<int>;

template<class T> bool ckmin(T& a, T b) { return b < a ? a = b, true : false; }
template<class T> bool ckmax(T& a, T b) { return a < b ? a = b, true : false; }

const int N = 1e5+7;

struct Ninja {
    int l, r, t;
};

bool operator < (Ninja a, Ninja b) { // mai vedem
    return a.r - a.l <= b.r - b.l;
}

Ninja a[N];

int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    
    int n, k, m; cin >> n >> k >> m;
    for (int i = 1; i <= m; ++i) cin >> a[i].l >> a[i].r >> a[i].t;
    sort(a + 1, a + m + 1);

    vector<int> b(n + 1, -1);
    
    vector<int> rem;
    for (int i = 1; i <= m; ++i) rem.push_back(i);

    while (!rem.empty()) {
        vector<int> nwrem;
        for (auto i : rem) {
            int l = a[i].l;
            int r = a[i].r;
            int t = a[i].t;
            if (t == 0) {
                for (int j = l; j <= r; ++j) b[j] = 0;
            } else {
                int cnt = 0;
                for (int j = l; j <= r; ++j) cnt += b[j] == 0;
                if (cnt == r - l) {
                    for (int j = l; j <= r; ++j) {
                        if (b[j] == -1) b[j] = 1;
                    }
                } else {
                    nwrem.push_back(i);
                }
            }
        }
        if (nwrem.size() == rem.size()) break;
        rem = nwrem;
    }
    int cnt = 0;
    for (int i = 1; i <= n; ++i) {
        if (b[i] == 1) cout << i << "\n", ++cnt;
    }
    if (cnt == 0) cout << -1 << "\n";
}