#include <bits/stdc++.h>
using namespace std;
const int MAXn = 1e5 + 10;

int deg[MAXn], n, m;
int main() {
	cin >> n >> m;
	for (int i = 0; i < m; i++) {
		int u, v;
		cin >> u >> v;
		deg[u]++;
		deg[v]++;
	}
	for (int i = 1; i <= n; i++)
		if (deg[i] % 2)
			return cout << "NO",0;
	cout << "YES";
	
}