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

const int N = 1e5 + 10;
int n, q, cnt[N];

int main() {
	cin >> n >> q;
	for (int i = 0; i < q; i++) {
		int v, u;
		cin >> v >> u;
		v--;
		u--;
		cnt[v]++;
		cnt[u]++;
	}
	
	for (int i = 0; i < n; i++)
		if (cnt[i] & 1)
			return cout << "NO", 0;
	cout << "YES";
}
