#include <cstdio>
#include <algorithm>
int N, M, a[100001];
int main()
{
	scanf("%d%d", &N, &M);
	for (int i = 1, u, v; i <= M; i++)
	{
		scanf("%d%d", &u, &v);
		a[u] ^= 1;
		a[v] ^= 1;
	}
	printf(int(std::count(a + 1, a + N + 1, 0)) == N ? "YES" : "NO");
	return 0;
}
