#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

vector<int> g[100000];
int used[100000];
vector<int> order;

bool flag = 0;

void dfs(int v) {
    used[v] = 1;
    for (int u: g[v]) {
        if (!used[u])
            dfs(u);
        else if (used[u] == 1)
            flag = 1;
    }
    used[v] = 2;
    order.push_back(v);
}


int main() {
    int n, m;
    cin >> n >> m;
    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        u--; v--;
        g[u].push_back(v);
    }
    for (int i = 0; i < n; i++) {
        if (!used[i])
            dfs(i);
    }
    reverse(order.begin(), order.end());
    for(int i = 1; i < order.size(); i++) {
        for (int j = 1; j < n; j++) {
            if (g[order[i - 1]][j] != order[i]) {
                cout << "NO";
                exit(0);
            }
        }
    }
    if (flag)
        cout << "NO";
    else {
        cout << "YES" << '\n';
        for (int v: order) {
            cout << v + 1;
            cout << ' ';
        }
    }
    return 0;
}