#include <bits/stdc++.h>
using namespace std;
int n,m,ind[50];
vector<int> a[50];
vector<int> res;
int main(){
cin >> n >> m;
for (int i=0;i<m;i++){
int u,v;
cin >> u >> v;
a[u].push_back(v);
ind[v];
}
priority_queue<int,vector<int>,greater<int> > q;
for (int i=1;i<=n;i){
if (ind[i]==0) q.push(i);
}
while (!q.empty()){
int now = q.top();
q.pop();
res.push_back(now);
for (int i=0;i<a[now].size();i++){
int next=a[now][i];
ind[next]--;
if (ind[next]==0) q.push(next);
}
}
if (res.size()!=n){
cout << "has circle.";
}else{
for (int i=0;i<n;i++){
cout << res[i] << ' ';
}
}
return 0;
}
