#include 
#include 
using namespace std;
int n, m;
vector graph[1005];
bool visited[1005];
void dfs(int node) {
    visited[node] = true;
    cout << node << " ";
    for(int i = 0; i < graph[node].size(); i++) {
        int sosed = graph[node][i];
        if(!visited[sosed]) {
            dfs(sosed);
        }
    }
}
int main() {
    cin >> n >> m;
    memset(visited, false, sizeof visited);
    for(int i = 0; i < m; i++) {
        int a,b;
        cin >> a >> b;
        graph[a].push_back(b);
    }
    dfs(0);
    return 0;
}