#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using vll = vector<long long>;
using vvll = vector<vector<long long>>;
using vb = vector<bool>;
using vvb = vector<vector<bool>>;
using vs = vector<string>;
#define lln \
  ll n;     \
  cin >> n;
#define REP(i, n) for (long long i = 0; i < n; i++)
#define REP2(i, s, e) for (long long i = s; i < e; i++)
#define UNIQUE_VECTOR(v) v.erase(unique(v.begin(), v.end()))
ll gcd(ll x, ll y) { return (x % y) ? gcd(y, x % y) : y; }
ll lcm(ll x, ll y) { return x / gcd(x, y) * y; }
class UNIONFIND_TREE {
 private:
  unordered_map<ll, ll> parents;
  unordered_map<ll, ll> sizes;

 public:
  void add(ll x) {
    parents[x] = x;
    sizes[x] = 1;
    return;
  }
  void add(ll parent, ll x) {
    parents[x] = parents[parent];
    sizes[parents[x]] += 1;
    return;
  }
  ll findRoot(ll x) {
    if (x == parents[x]) {
      return x;
    }
    ll ret = findRoot(parents[x]);
    parents[x] = ret;
    return ret;
  }
  void bond(ll x, ll y) {
    x = findRoot(x);
    y = findRoot(y);
    if (x != y) {
      if (sizes[x] > sizes[y]) {
        sizes[x] += sizes[y];
        parents[y] = x;
      } else {
        sizes[y] += sizes[x];
        parents[x] = y;
      }
    }
    return;
  }
  ll size(ll x) {
    ll ret = sizes[findRoot(x)];
    return ret;
  }
};
int main() {
  ll n, m;
  UNIONFIND_TREE G;
  cin >> n >> m;
  REP(i, 2 * n) { G.add(i + 1); }
  ll a, b;
  REP(i, m) {
    cin >> a >> b;
    G.bond(a, b + n);
    G.bond(a + n, b);
  }
  REP(i, n) {
    if (G.findRoot(i + 1) != G.findRoot(i + 1 + n)) {
      cout << "No" << endl;
      return 0;
    }
  }
  cout << "Yes" << endl;
  return 0;
}