#include <bits/stdc++.h>
using namespace std;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T>
void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x) cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v)) cerr << ", ";
  _print(v...);
}
vector<long long> adj[200005];
void solve() {
  long long n, m;
  cin >> n >> m;
  for (long long i = 0; i < m; i++) {
    long long u, v;
    cin >> u >> v;
    adj[u].push_back(v);
    adj[v].push_back(u);
  }
  vector<long long> cnt(n + 1);
  vector<long long> a(n + 1);
  queue<long long> q;
  for (long long i = 1; i < n + 1; i++) {
    cin >> a[i];
    if (!a[i]) q.push(i);
  }
  vector<long long> ans;
  vector<long long> vis(n + 1);
  while (!q.empty()) {
    long long p = q.front();
    q.pop();
    cnt[p]++;
    ans.push_back(p);
    for (auto x : adj[p]) {
      cnt[x]++;
      if (cnt[x] == a[x]) q.push(x);
    }
  }
  cout << ans.size() << "\n";
  for (auto x : ans) cout << x << " ";
  cout << "\n";
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long t;
  t = 1;
  for (long long i = 0; i < t; i++) {
    solve();
  }
}
