#include <iostream>
#include <fstream>
#include <queue>
#include <string.h>
#define N 10000

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

vector <int> L[N];
int n,m,viz[N];

void Read()
{
    int x,y;
    f >> n >> m;
    for(int i = 1; i <= m;i++)
    {
        f >> x >> y;
        L[x].push_back(y);
    }
}
void DF(int nod)
{
    int k,i;
    cout << nod << " ";
    viz[nod] = 1;
    for(k = 0; k < L[nod].size();k++)
    {
        i = L[nod][k];
        if(!viz[i])
            DF(L[nod][k]);
    }
}
int main()
{
    memset(viz,0,N);
    Read();
    int p = 0;
    for(int i = 1; i <= n;i++)
        if(!viz[i])
        {
            p++;
            DF(i);
        }
    g << p;
    return 0;
}