#include <iostream>
#include <vector>
#include <stack>

using namespace std;

int topoNum;

enum COLOR {
    WHITE, GRAY, BLACK
};

COLOR* color;
int* topoNums;

bool has_cycle;

stack<int> res;

void topo_order(const vector<vector<int> >& adj, int u){
    color[u] = GRAY;

    for(int v : adj[u]){
        if(color[v] == WHITE){
            topo_order(adj, v);
            if(has_cycle)return;
        }else{
            if(color[v] == GRAY){
                has_cycle = true;
                return;
            }
        }
    }

    topoNum --;
    topoNums[u] = topoNum;
    color[u] = BLACK;
    res.push(u);
}

void dfs_wrapper(const vector<vector<int> >& adj, int n){

    for(int i = 1; i <= n; i ++)color[i] = WHITE;

    for(int i = 1; i <= n; i ++){
        if(color[i] == WHITE){
            topo_order(adj, i);
        }
    }
}

void print(int n){
    while(n--){
        int t = res.top();
        res.pop();
        printf("%d ", t);
    }
    puts("");
}

void addArc(int x, int y, vector<vector<int> >& adj){
    adj[x].push_back(y);
}

int main(){
    int n, m;
    scanf("%d%d", &n, &m);
    vector<vector<int> > adj;
    adj.resize(n+1);
    topoNum = n + 1;
    color = new COLOR[n+1];
    topoNums = new int[n+1];

    for(int i = 1; i <= m; i ++){
        int x, y;
        scanf("%d%d", &x, &y);
        addArc(x, y, adj);
    }

    dfs_wrapper(adj, n);
    if(has_cycle)puts("-1");
    else print(n);

    delete[] topoNums;
    delete[] color;
    return 0;
}