#include <iostream>
#include <vector>
#include <fstream>
#include <stack>

using namespace std;

ifstream fin ("sortaret.in");
ofstream fout ("sortaret.out");

const int N_MAX=50005;

vector<int> ad[N_MAX];
vector<int> ordine;
bool checked[N_MAX];

void dfs (int node) {
    if (checked[node]) return;
    for (vector<int>::iterator it = ad[node].begin(); it != ad[node].end(); it++) {
        if (!checked[*it]) dfs(*it);
    }
    checked[node] = 1;
    ordine.push_back(node);
}

int main()
{
    int n, m;

    fin >> n >> m;

    for (int i=1; i <= m; i++) {
        int to, from;
        fin >> from >> to;
        ad[from].push_back(to);
    }

    for (int i=1; i <= n; i++) {
        if (!checked[i]) dfs(i);
    }

    while (!ordine.empty()) {
        fout << ordine.back();
        ordine.pop_back();
    }

    return 0;
}