#include "bits/stdc++.h"
using namespace std;

#define ll long long

void solve() {
    int n, m;
    cin >> n >> m;

    vector<set<pair<ll, ll>>> gy(n + 1, set<pair<ll, ll>>());
    for (int i = 0; i < m; i++) {
        int y;
        ll x1, x2;
        cin >> x1 >> y >> x2 >> y;

        gy[y].insert({x1, x2});
    }

    set<pair<ll, int>> hx;
    for (int i = 0; i < n; i++) hx.insert({i + 1, i});

    for (auto& s : gy) {
        for (auto p : s) {
            set<int> iv;

            auto it = hx.lower_bound({p.first, -1});
            while (it != hx.end() && it->first == p.first) {
                int i = it->second;
                iv.insert(i);
                hx.erase(it);
                hx.insert({p.second, i});
                it = hx.lower_bound({p.first, i + 1});
            }

            it = hx.lower_bound({p.second, -1});
            while (it != hx.end() && it->first == p.second) {
                int i = it->second;
                if (iv.find(i) != iv.end()) {
                    it = hx.lower_bound({p.second, i + 1});
                    continue;
                }
                hx.erase(it);
                hx.insert({p.first, i});
                it = hx.lower_bound({p.second, i + 1});
            }
        }
    }

    vector<ll> h(n);
    for (auto p : hx) {
        h[p.second] = p.first;
    }

    for (ll x : h) cout << x << '\n';
}

int main() {
    solve();
}