#include <fstream>
#include <cstring>
#include <algorithm>
#include <queue>
using namespace std;

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

const int MAXN = 50005;
const int MAXM = 100005;
int n, m;
vector<int> v[MAXN];
int r[MAXN];
queue<int> q;
bool viz[MAXN];

void dfs(int k) {
    q.push(k);
    viz[k] = 1;
    for (int i = 0; i < v[k].size(); ++i) {
        if (viz[v[k][i]] == 0) {
            dfs(v[k][i]);
        }
    }
}

int main() {

    fin >> n >> m;
    for (int i = 1; i <= n; ++i) {
        int a, b;
        fin >> a >> b;
        v[a].push_back(b);
        r[b]++;
    }

    for (int i = 1; i <= n; ++i) {
        if (r[i] == 0) {
            dfs(i);
            i = n + 10;
        }
    }

    while (!q.empty()) {
        fout << q.front()<< ' ';
        q.pop();
    }

    fout.close();
    return 0;
}