#include <cstdio>
#include <cstring>
#include <vector>
using namespace std;
#define MAXN 50100
#define pb push_back
int n,m,deg[MAXN],q[MAXN]; 
vector <int> G[MAXN];
vector<int>::iterator it;
int main()
{
    int i,a,b,x;
	freopen("sortaret.in","rt",stdin);
    freopen("sortaret.out","wt",stdout);
    scanf("%d%d\n",&n,&m);
    for(i=1;i<=m;i++)
        {
		scanf("%d %d\n", &a, &b);
		G[a].pb(b);
		deg[b]++;
		}
    for(x=1;x<=n;x++)
     if(deg[x]==0) q[++q[0]]=x;
    for(i=1;i<=n;i++)
    {
        x=q[i];
        for(it=G[x].begin();it!=G[x].end();++it)
        {
            deg[*it]--;
            if(deg[*it]==0) q[++q[0]]=*it;
        }
    }
    for(i=1;i<=n;i++)
        printf("%d",q[i]);
    return 0;
}