#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cmath>
#include <map>
#include <stack>
#include <queue>
#include <cstdlib>
#include <numeric>


/*
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::::. <!!!!!! !!!!!!!!!! ,$ .nn.' "$$ P"   <!!!!!!!!!!!' .::::::::::::::::
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MMMM' <!!!,MMM "$$$$$$P dMM>;!!! 4MMMMMMb :::::.. "-=cczyycc??" .:::::::::
MMMP <!!! dMMMb "?$$P" uMMM>;!!! 4MMMMMMMr`:::::::::.........:::::::::::::
MMP';!!! ;MMMMMMn,.".uMMMMM ;!!! MMMMMMMMM,`::::::::::::::::::::::::::::::
MM ;!!!! MMMMMMMMMMMMMMMMMM !!!! MMMMMMMMMb `:::::::::::::::::::::::::::::
M" !!!! uMMMMMMMMMMMMMMMMMP !!! ;MMMMMMMMMMx :::::::::::::::::::::::::::::
P.!!!! ,MMMMMMMMMMMMMMMMMM ,!!! MMMMMMMMMMMMx`::::::::::::::::::::::::::::
!!!!> MMMMMMMMMMMMMMMMMMP !!!',MMMMMMMMMMMMM `:::::::::::::::::::::::::::
*/


int main()
{
	long long a, b;

	std::cin >> a >> b;

	std::map<long long, long long > m;

	for (long long i = 0; i < b; i++) {
		long long c, d;

		std::cin >> c >> d;

		m[c]++;
		m[d]++;
	}

	for (auto it = m.begin(); it != m.end(); it++) {
		if (it->second % 2 == 1) {
			std::cout << "NO" << std::endl;
			return 0;
		}
	}

	std::cout << "YES" << std::endl;

	return 0;
}

Measured memory_bytes: 5632