FoodWeb

#include <bits/stdc++.h>
using namespace std;
using pii=pair<int,int>;
bool check=0;
vector<int> H[100010];
bool v[100010];

void DFS(int i){
    v[i]=1;
    for(auto x:H[i]){
        if(v[x]){
            check=1;
            return;
        }else DFS(x);
        if(check==1) return;
    }
    v[i]=0;
}

int main(){
    int V,E,h,p;
    scanf("%d%d",&V,&E);
    vector<bool> visited(V+10,false);
    vector<int> hunted(V+10,0);
    queue<int> Q;
    priority_queue<pii,vector<pii>,greater<pii>> q;
    for(int i=0;i<E;i++){
        scanf("%d%d",&p,&h);
        H[h].push_back(p);
        hunted[p]++;
    }
    for(int i=1;i<=V;i++){
        check=0;
        DFS(i);
        if(check==1) break;
    }
    if(check==1){
        printf("No");
        return 0;
    }
    for(int i=1;i<=V;i++){
        if(hunted[i]==0){
            q.push({0,i});
            while(!q.empty()){
                int r=q.top().first;
                int c=q.top().second;
                Q.push(c);
                q.pop();
                visited[c]=true;
                for(auto x:H[c]){
                    if(hunted[x]>1){
                        hunted[x]--;
                        continue;
                    }else q.push({r+1,x});
                }
            }
        }
    }
    printf("Yes\n");
    while(!Q.empty()){
        printf("%d ",Q.front());
        Q.pop();
    }
}