#include<iostream>
#include<algorithm>
#include<cmath>
#include<cstdio>
#include<vector>
#include<queue>
using namespace std;
int n, perm[512], m, in[512];
vector<int> v[512];
queue<int> q;

int main()
{
    freopen ("lottery.in", "r", stdin);
    freopen ("lottery.out", "w" , stdout);
    scanf("%d", &n);

    for (int i=1; i<=n; i++)
    {
        int x, y;
        scanf("%d%d", &x, &y);
        in[y]++;
        v[x].push_back(y);
        m=max(m,x);
        m=max(m,y);
    }
    for (int i=1; i<=m; i++)
    {
        if (in[i]==0)
        {
            q.push(i);
            break;
        }
    }
    for (int i=1; i<m; i++)
    {
        int x=q.front();
        q.pop();
        printf("%d ", x);
        for (int j=0; j<v[x].size(); j++)
        {
            int y=v[x][j];
            in[y]--;
            if (in[y]==0)
            {
                q.push(y);
            }
        }
    }
    printf("%d\n", q.front());
    return 0;
}