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

int i, n, x, y, grad[100005], m;

int main() {
  ios_base::sync_with_stdio(0);

  for(cin >> n >> m; m; --m) {
    cin >> x >> y;
    ++grad[x]; ++grad[y];
  }

  for(i = 1; i <= n; ++i) if(grad[i] & 1) return cout << "NO\n", 0;

  cout << "YES\n";

  return 0;
}