#include<iostream>
#include<vector>
#include<queue>
using namespace std;
vector<int>graph[10];
int t;
int discover[10];
int finish[10];
int color[10];
int prev[10];
void dfs_visit(int u);
void dfs(int node)
{
    for(int u=0;u<node;u++)
    {
        if(color[u]==0)
            dfs_visit(u);
    }
}
void dfs_visit(int u)
{   color[u]=1;
    t=t+1;
    discover[u]=t;
    for(int i=0;i<graph[u].size();i++)
    {
        if(color[graph[u][i]]==0)
            prev[graph[u][i]]=u;
            dfs_visit(graph[u][i]);
    }
    t=t+1;
    finish[u]=t;
    color[u]=2;
}

int main()
{
    int node,edge;
    cin>>node>>edge;
    for(int i=0;i<edge;i++)
    {
        int x,y;
        cin>>x>>y;
        graph[x].push_back(y);
    }
    //now calling dfs
    dfs(node);
    for(int i=0;i<node;i++)
    {
        cout<<"Discover t of "<<i<<" "<<discover[i]<<" & finish t "<<finish[i]<<"."<<endl;
    }
    return 0;
}