#include <iostream>
#include <vector>
#include <queue>
#include <stack>

using namespace std;
vector<bool> is_in_stack, visited;
vector<vector<int>> adj;
stack<int> ordered;

void DFS(int node)
{
    is_in_stack[node] = true;
    visited[node] = true;
    for(int i = 0; i < adj[node].size(); i++){
        int newNode = adj[node][i];
        if(is_in_stack[newNode]){
            cout << "NEM";
            exit(0);
        }
        if(!visited[newNode]){
            DFS(newNode);
        }
    }
    ordered.push(node);
    is_in_stack[node] = false;
}

int main()
{
    int N, M;
    cin >> N >> M;
    adj.resize(2*N+2);
    is_in_stack.assign(2*N+2, false);
    visited.assign(2*N+2, false);
    for(int i = 1; i <= N; i++){
        adj[i].push_back(i+N);
    }
    for(int i = 0; i < M; i++){
        int tipus, u, v;
        cin >> tipus >> u >> v;
        //u az intervallum kezdetet, u+N a veget mutato csomopont
        if(tipus == 1){
            adj[v].push_back(u+N);
            adj[u].push_back(v+N);
        }
        else{
            adj[u+N].push_back(v);
        }
    }
    for(int i = 1; i <= N; i++){
        if(!visited[i]){
            DFS(i);
        }
    }

    vector<int> left(N+1), right(N+1);

    int index = 1;
    while(!ordered.empty()){
        int node = ordered.top();
        ordered.pop();
        if(node > N){
            right[node - N] = index;
        }
        else{
            left[node] = index;
        }
        index++;
    }
    cout << "IGEN\n";

    for(int i = 1; i <= N; i++){
        cout << left[i] << " " << right[i] << endl;
    }
    return 0;
}


/*
ha eltek egyutt: ru >= lv && lu <= rv <=> lv <= ru && lu <= rv
ha u a v elott elt: ru <= lv
*/