#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  dsu d(2 * n);
  rep(_, m) {
    int i, j;
    string e;
    cin >> i >> e >> j;
    i--, j--;
    if (e[2] == '/') {
      d.merge(i, n + j);
      d.merge(i + n, j);
    } else {
      d.merge(i, j);
      d.merge(i + n, j + n);
    }
  }
  rep(i, n) if (d.same(i, i + n)) {
    cout << "No\n";
    return 0;
  }
  cout << "Yes\n";
  vector<char> done(n);
  VI ans;
  for (const auto& g : d.groups()) {
    if (done[g[0] % n]) continue;
    for (int x : g) done[x % n] = true;
    int c[2]{};
    for (int x : g) c[x >= n]++;
    if (c[0] > c[1]) {
      for (int x : g) if (x < n) ans.emplace_back(x);
    } else {
      for (int x : g) if (x >= n) ans.emplace_back(x - n);
    }
  }
  int sz = ans.size();
  cout << sz << '\n';
  rep(i, sz) cout << ans[i] + 1 << " \n"[i + 1 == sz];
}