fun intList() = readLine()?.split(" ")?.map(String::toInt) ?: TODO()
fun main() {
    val (n, m) = intList()
    val count = hashMapOf<Int, Int>()
    repeat(m) {
        val (a, b) = intList()
        count[a] = count.getOrDefault(a, 0) + 1
        count[b] = count.getOrDefault(b, 0) + 1
    }
    if (count.values.all { it % 2 == 0 }) {
        println("YES")
    } else {
        println("NO")
    }
}
