#include <bits/stdc++.h>
using namespace std;
vector<vector<int> > g, g2, comp;
vector<int> ind, tops, op, c;
vector<bool> inq;
int n, last = 1, cur = 0;

void dfs(int v){
    c[v] = cur;
    comp[cur].push_back(v);
    for (int x : g2[v]){
        if (c[x] < 0){
            dfs(x);
        }
    }
}

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();
        if (op[v]) continue;
        for (int x : comp[c[v]]){
            if (x == v) continue;
            if (!inq[x]){
                inq[v] = 1;
            }
        }
        if (!inq[v]){
            for (int x : comp[c[v]]){
                op[x] = last;
                for (int y : g[x]){
                    ind[y]--;
                    if (!ind[y]) q.push(y);
                }
            }
            last += 2;
        }
    }
}

int main()
{
    int m;
    cin >> n >> m;
    g.resize(n+1);
    g2.resize(n+1);
    comp.resize(n+1);
    inq.assign(n+1, 0);
    ind.assign(n+1, 0);
    c.assign(n+1, -1);
    op.assign(n+1, 0);
    while (m--){
        int t, a, b;
        cin >> t >> a >> b;
        if (t == 2){
            g[a].push_back(b);
            ind[b]++;
        }
        else{
            g2[a].push_back(b);
            g2[b].push_back(a);
        }
    }
    for (int i=1; i<=n; i++){
        if (c[i] < 0){
            comp.push_back({});
            dfs(i);
            cur++;
        }
    }
    bfs();
    for (int i=1; i<=n; i++){
        if (!op[i]){
            cout << "NEM";
            return 0;
        }
    }
    cout << "IGEN";
    for (int i=1; i<=n; i++){
        cout << "\n" << op[i] << " " << op[i] + 1;
    }
}