#include <bits/stdc++.h>

//#include <atcoder/all>
using namespace std;

#define lli long long int
#define REP(i, s, n) for (lli i = s; i < n; i++)
#define INF (1LL << 62)
#define mp(a, b) make_pair(a, b)
#define SORT(V) sort(V.begin(), V.end())
#define PI (3.141592653589794)
#define TO_STRING(VariableName) #VariableName
#define LOG1(x)                                                                \
  if (DEBUG)                                                                   \
    cout << TO_STRING(x) << "=" << x << " " << endl;
#define LOG2(x, y)                                                             \
  if (DEBUG)                                                                   \
    cout << TO_STRING(x) << "=" << x << " " << TO_STRING(y) << "=" << y << endl;
#define LOG3(x, y, z)                                                          \
  if (DEBUG)                                                                   \
    cout << TO_STRING(x) << "=" << x << " " << TO_STRING(y) << "=" << y << " " \
         << TO_STRING(z) << "=" << z << endl;
#define LOG4(w, x, y, z)                                                       \
  if (DEBUG)                                                                   \
    cout << TO_STRING(w) << "=" << w << " " << TO_STRING(x) << "=" << x << " " \
         << TO_STRING(y) << "=" << y << " " << TO_STRING(z) << "=" << z        \
         << endl;
#define LOG5(w, x, y, z, a)                                                    \
  if (DEBUG)                                                                   \
    cout << TO_STRING(w) << "=" << w << " " << TO_STRING(x) << "=" << x << " " \
         << TO_STRING(y) << "=" << y << " " << TO_STRING(z) << "=" << z << " " \
         << TO_STRING(a) << "=" << a << endl;
#define LOG6(w, x, y, z, a, b)                                                 \
  if (DEBUG)                                                                   \
    cout << TO_STRING(w) << "=" << w << " " << TO_STRING(x) << "=" << x << " " \
         << TO_STRING(y) << "=" << y << " " << TO_STRING(z) << "=" << z << " " \
         << TO_STRING(a) << "=" << a << " " << TO_STRING(b) << "=" << b        \
         << endl;

#define overload6(a, b, c, d, e, f, g, ...) g
#define LOG(...)                                                               \
  overload6(__VA_ARGS__, LOG6, LOG5, LOG4, LOG3, LOG2, LOG1)(__VA_ARGS__)

template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

mt19937 engine;
std::chrono::system_clock::time_point start, endTime;

std::ostream &operator<<(std::ostream &dest, __int128_t value) {
  std::ostream::sentry s(dest);
  if (s) {
    __uint128_t tmp = value < 0 ? -value : value;
    char buffer[128];
    char *d = std::end(buffer);
    do {
      --d;
      *d = "0123456789"[tmp % 10];
      tmp /= 10;
    } while (tmp != 0);
    if (value < 0) {
      --d;
      *d = '-';
    }
    int len = std::end(buffer) - d;
    if (dest.rdbuf()->sputn(d, len) != len) {
      dest.setstate(std::ios_base::badbit);
    }
  }
  return dest;
}

__int128 parse(string &s) {
  __int128 ret = 0;
  for (int i = 0; i < s.length(); i++) {
    if ('0' <= s[i] && s[i] <= '9') {
      ret = 10 * ret + s[i] - '0';
    }
  }
  return ret;
}

#define DEBUG 0

// checker https://atcoder.jp/contests/abc264/tasks/abc264_e

struct UnionFind {
  vector<int> par; // par[i]:iの親の番号　(例) par[3] = 2 : 3の親が2
  vector<bool> isOk;
  vector<lli> siz; // 素集合のサイズを表す配列(1 で初期化)
  lli N;

  UnionFind(int N)
      : par(N), isOk(N), siz(N) { //最初は全てが根であるとして初期化
    for (int i = 0; i < N; i++) {
      par[i] = i;
      isOk[i] = false;
      siz[i] = 1;
    }

    this->N = N;
  }

  int root(int x) { // データxが属する木の根を再帰で得る：root(x) = {xの木の根}
    if (par[x] == x)
      return x;
    return par[x] = root(par[x]);
  }

  void setOk(lli i) { isOk[i] = isOk[root(i)] = true; }

  bool isCheckOk(lli i) { return isOk[root(i)]; }
  void unite(int x, int y) { // xとyの木を併合
    int rx = root(x);        // xの根をrx
    int ry = root(y);        // yの根をry
    if (rx == ry)
      return; // xとyの根が同じ(=同じ木にある)時はそのまま

    if (siz[rx] < siz[ry])
      swap(rx, ry);
    siz[rx] += siz[ry];
    par[ry] =
        rx; // xとyの根が同じでない(=同じ木にない)時：xの根rxをyの根ryにつける
    if (isOk[rx] || isOk[ry]) {
      isOk[ry] = true;
      isOk[rx] = true;
    }
  }

  bool same(int x, int y) { // 2つのデータx, yが属する木が同じならtrueを返す
    int rx = root(x);
    int ry = root(y);
    return rx == ry;
  }
  lli size(lli x) { return siz[root(x)]; }
};

lli color[110];

void solve() {
  //  write your code here
  lli N, M;
  cin >> N >> M;

  vector<lli> A(M), B(M);
  vector<vector<lli>> G(N);
  REP(i, 0, M) {
    cin >> A[i] >> B[i];
    A[i]--;
    B[i]--;
    G[A[i]].push_back(B[i]);
    G[B[i]].push_back(A[i]);
  }

  REP(i, 0, N) color[i] = -1;

  REP(i, 0, N) {
    if (color[i] != -1)
      continue;

    queue<lli> q;
    q.push(i);
    color[i] = 0;
    while (q.size()) {
      lli now = q.front();
      q.pop();
      for (auto next : G[now]) {
        if (color[next] == -1) {
          color[next] = 1 - color[now];
          q.push(next);
        } else {
          if (color[next] == color[now]) {
            cout << "No" << endl;
            return;
          }
        }
      }
    }
  }
  cout << "Yes" << endl;
}

// Generated by 2.13.0 https://github.com/kyuridenamida/atcoder-tools  (tips:
// You use the default template now. You can remove this line by using your
// custom template)
int main() {
  // Failed to predict input format

  lli N = 1;
  // cin >> N;
  while (N--)
    solve();

  return 0;
}