#include <bits/stdc++.h>
using namespace std;

const int N = 1e5 + 7;

int a[N];
int n, m;

int main() {
	cin >> n >> m;
	while (m--) {
		int x, y;
		cin >> x >> y;
		a[x]++;
		a[y]++;
	}
	for (int i = 1; i <= n; i++) 
		if (a[i] % 2) {
			cout << "NO";
			return 0;
		}
	cout << "YES";

	return 0;
}
