#include <iostream>
#include<fstream>
#include<vector>
#include<queue>
using namespace std;

int n,m,start;

const int inf = 10000000;
int viz[100001];
vector<int>d;
queue<int>Q;
vector<int>L[100001];
vector<int>v;
vector<int>t;
vector<int>grad;
ifstream fin("sortaret.in");
ofstream fout("sortaret.out");

void citire()
{
    int i,j;
    fin>>n>>m;
    grad.resize(n+1,0);

    for(i=1;i<=n;i++)
    {
        int x,y;
        fin>>x>>y;
        L[x].push_back(y);
        grad[y]++;
    }

    for(i=1;i<=n;i++)
        if(grad[i] == 0)
            {
                Q.push(i);
                v.push_back(i);
            }
}

void sort_top()
{
    int i,j,x,y,z;

    while(!Q.empty())
    {
        x=Q.front();
        Q.pop();
        for(auto p:L[x])
        {
            grad[p]--;
            if(grad[p] == 0)
                {
                Q.push(p);
                v.push_back(p);
                }
        }
    }

    if(v.size() == n)
        for(auto p : v)
            fout<<p<<" ";
    else fout<<"Graf neconex";
}

int main()
{
    citire();
    sort_top();
}