#define _CRT_SECURE_NO_WARNINGS
#include <cstdio>
#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <algorithm>

using namespace std;

bool dfs(vector<vector<int>>& lin, vector<int>& answer, vector<bool>& use, int& c, int& n)
{
	if (use[c] && answer[c] == 0)
		return false;
	use[c] = true;
	bool sortable = true;
	for (int i = 1; i < lin[c].size(); i++)
	{
		//if (use[i] && answer[i] == 0)
		//return false;
		if (!use[i])
			sortable = sortable && dfs(lin, answer, use, lin[c][i], n);
	}
	answer[n] = c;
	n -= 1;
	return sortable;
}

int main()
{
	int n, m, a, b, d;
	scanf("%d %d", &n, &m);
	d = n;
	vector<vector<int>> line(n + 1, vector<int>(1));
	for (int i = 1; i < m; i++)
	{
		scanf("%d %d", &a, &b);
		line[a].push_back(b);
	}
	vector<int> ans(n + 1, 0);
	vector<bool> used(n + 1, false);
	for (int i = 1; i <= d; i++)
		if (!used[i])
			if (!dfs(line, ans, used, i, n))
			{
				printf("No");
				return 0;
			}

	printf("Yes\n");
	for (int i = 1; i <= d; i++)
		printf("%d ", ans[i]);

	system("pause");
	return 0;
}