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

int n, m, f[100001];
int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin >> n >> m;
	for(int i = 0, a, b; i < m; i++) {
		cin >> a >> b;
		f[a]++;
		f[b]++;
	}
	for(int i = 1; i <= n; i++) if(f[i] % 2) cout << "NO", exit(0);
	cout << "YES";
}
