#include <bits/stdc++.h>
using namespace std;
int n, m;
vector<int> G[100000];
int a[100000];
int b[100000];
int c[100000];
void dfs(int v) {
  b[v]++;
  c[v] = 1;
  for (int i = 0; i < (int)(G[v].size()); i++) {
    int w = G[v][i];
    if (++b[w] == a[w]) dfs(w);
  }
}
int main() {
  cin >> n >> m;
  for (int i = 0; i < (int)(m); i++) {
    int a, b;
    cin >> a >> b;
    --a, --b;
    G[a].push_back(b);
    G[b].push_back(a);
  }
  for (int i = 0; i < (int)(n); i++) cin >> a[i];
  for (int i = 0; i < (int)(n); i++) {
    if (a[i] == b[i]) dfs(i);
  }
  cout << accumulate(c, c + n, 0) << endl;
  for (int i = 0; i < (int)(n); i++)
    if (c[i]) cout << i + 1 << " ";
  cout << endl;
  return 0;
}
