#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#define count masloriy1489
#define y1 jhgfds
#define ll long long
#define double long double
#define pb push_back
#define eb emplace_back
#define all(v) v.begin(), v.end()
#define rep(i, n) for(int i = 0; i < n; i++)

using namespace std;
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);

int n, m;
vector<int> a[100001];
int used[100001] = {0};
vector<int> res;
int t = -1;
bool f = false;
bool g = false;

void dfs(int x){
    used[x] = 1;
    if(f)
        return;
    for(int i : a[x]) {
        if(used[i] == 0)
            dfs(i);
        else if(used[i] == 1){
            f = true;
            t = i;
            res.push_back(x + 1);
            return;
        }
        if(f){
            if(!g)
                res.push_back(x + 1);
            if(x == t)
                g = true;
            return;
        }
    }
    used[x] = 2;
}

int main(){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    freopen("cycle2.in", "r", stdin);
    freopen("cycle2.out", "w", stdout);
    cin >> n >> m;
    int x, y;
    for(int i = 0; i < m; i++){
        cin >> x >> y;
        x--; y--;
        if(x == y){
            cout << "YES\n" << (x+1);
            return 0;
        }
        a[x].push_back(y);
    }
    for(int i = 0; i < n; i++){
        if (!used[i]) {
            dfs(i);
        }
    }
    if(!res.empty()){
        cout << "YES\n";
        reverse(res.begin(), res.end());
        for(int &j : res) {
            cout << j << " ";
        }
    }else{
        cout << "NO";
    }
}