#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

int n, m, t, a, b;
vector <vector <int>> g(2e5 + 1);
vector <bool> ent(2e5 + 1, false);
vector <bool> lef(2e5 + 1, false);
vector <int> tp;
vector <int> ans(2e5 + 1, 0);

void get_tp(int x) {
    if (ent[x] && !lef[x]) { cout << "NEM"; exit(0); }
    if (ent[x]) return;
    ent[x] = true;
    for (int i : g[x]) get_tp(i);
    lef[x] = true;
    tp.push_back(x);
}

int main()
{
    cin >> n >> m;
    for (int i = 1; i <= n; i++) g[i].push_back(i + n);
    for (int i = 0; i < m; i++) {
        cin >> t >> a >> b;
        if (t == 1) {
            g[a].push_back(b + n);
            g[b].push_back(a + n);
        }
        if (t == 2) g[a + n].push_back(b);
    }
    for (int i = 1; i <= n; i++) get_tp(i);
    reverse(tp.begin(), tp.end());
    for (int i = 0; i < 2 * n; i++) ans[tp[i]] = i + 1;
    cout << "IGEN\n";
    for (int i = 1; i <= n; i++) cout << ans[i] << " " << ans[i + n] << endl;
}