#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
vector <int> v[1005];
vector <int> drum;
queue <int> q;
int grd[1005],vis[1005];
int vmax=-1,nr=0;
int n,m,i,j,a,b,ok,ciclu,marime,vf;

int main(){
    cin>>n>>m;
    for(i=1;i<=m;i++){
        cin>>a>>b;
        v[a].push_back(b);
        grd[b]++;
    }
    for(i=1;i<=n;i++){
        if(grd[i]==0){
            q.push(i);
        }
    }
    while(!q.empty()){
        vf=q.front();
        drum.push_back(vf);
        q.pop();
        nr++;
        for(int x : v[vf]){
            grd[x]--;
            if(grd[x]==0){
                q.push(x);
            }
        }
    }
    if(nr==n){
        for(int x : drum){
            cout<<x<<" ";
        }
    }
    else{
        cout<<"ciclu";
    }
}