#include <bits/stdc++.h>
using namespace std;
vector<vector<int> > g;
vector<int> ind;
vector<int> op;
int n, last = 1;

void bfs(){
    queue<int> q;
    for (int i=1; i<=n; i++){
        if (!ind[i]){
            q.push(i);
        }
    }
    while (!q.empty()){
        int v = q.front();
        q.pop();
        op[v] = last;
        last++;
        for (int x : g[v]){
            ind[x]--;
            if (!ind[x]) q.push(x);
        }
    }
}

int main()
{
    int m;
    cin >> n >> m;
    g.resize(2*n+1);
    ind.assign(2*n+1, 0);
    op.assign(2*n+1, 0);
    while (m--){
        int t, a, b;
        cin >> t >> a >> b;
        if (t == 2){
            g[a + n].push_back(b);
            ind[b]++;
        }
        else{
            g[b].push_back(a + n);
            g[a].push_back(b + n);
            ind[a+n]++;
            ind[b+n]++;
        }
    }
    for (int i=1; i<=n; i++){
        g[i].push_back(i + n);
        ind[i+n]++;
    }
    bfs();
    for (int i=1; i<=2*n; i++){
        if (!op[i]){
            cout << "NEM";
            return 0;
        }
    }
    cout << "IGEN";
    for (int i=1; i<=n; i++){
        cout << "\n" << op[i] << " " << op[i + n];
    }
}