#include<iostream>
#include<fstream>
#include<vector>
#include<string.h>
#define N_max 50005
using namespace std;
vector<int> G[N_max];
int coada[N_max];
int viz[N_max];
int k;
void DFS(int nod)
{
viz[nod]=1;
vector<int>::iterator it;
for(it=G[nod].begin();it!=G[nod].end();it++)
if(viz[*it]==0)
        DFS(*it);
coada[++k]=nod;
}

int main()
{int i,n,m,x,y;
    ifstream fin("sortaret.in");
    ofstream fout("sortaret.out");
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        G[x].push_back(y);
    }
    for(i=1;i<=n;i++)
       {if(viz[i]==0)
        DFS(i);
       }

for(i=k;i>=1;i--)
    fout<<coada[i];
}