#include <cstdio>
using namespace std;

int N, M, a[100005];

int main() {
	scanf("%d%d", &N, &M);
	for (int i = 0; i != M; ++i) {
		int x, y; scanf("%d%d", &x, &y);
		++a[x]; ++a[y];
	}
	for (int i = 2; i <= N; ++i) {
		if (a[i] & 1) {
			puts("NO");
			return 0;
		}
	}
	puts("YES");
	return 0;
}
