#include<cstdio>
#include<vector>
#include<queue>

using namespace std;

vector<int>gr[1000];
int n,m,deg[1000];

void init(){
    int from,to;
    scanf("%d %d",&n,&m);

    for(int i=0;i<m;i++){
        scanf("%d %d",&from,&to);

        deg[to]++;///calculate the + degree of the node
        gr[from].push_back(to);
    }
}

void toposort(){
    int node;
    vector<int>sorted;
    queue<int>ready;

    for(int i=0;i<n;i++){
        if(deg[i]==0)ready.push(i);///each node that has a degree of 0 can be taken as first
    }

    while(!ready.empty()){
        node=ready.front();
        ready.pop();

        sorted.push_back(node);

        for(int neighbor:gr[node]){///simulates deleting of an edge. Simply reduce the degree of the node
            deg[neighbor]--;
            if(deg[neighbor]==0)ready.push(neighbor);///if the degree is 0 we can take the node next
        }
    }

    if(sorted.size()!=n){
        printf("Impossible\n");
        return;
    }

    for(int i=0;i<n;i++){
        printf("%d ",sorted[i]);
    }
    printf("\n");
}

int main(){
    init();
    toposort();
}