#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<queue>
using namespace std;const int maxn=100010;
int n,m,k,x,u,v,tot;
bool vis[maxn];
bool check[maxn];
int deg[maxn];
int sum[maxn];
int ans[maxn];
int h[maxn],cnt=0;
struct edge{int to,next;
}G[maxn<<1];struct pos{double k;//����int now;//��ǰ��pos(double k=0,int now=0):k(k),now(now){}bool operator <(const pos &A)const{return k>A.k;}
};priority_queue<pos>Q;void add(int x,int y){++cnt;G[cnt].to=y;G[cnt].next=h[x];h[x]=cnt;}bool Get_check(double k){memset(check,0,sizeof(check));memset(deg,0,sizeof(deg));while(!Q.empty())Q.pop();for(int u=1;u<=n;++u){if(vis[u])continue;for(int i=h[u];i;i=G[i].next){int v=G[i].to;if(vis[v])continue;deg[v]++;}}for(int i=1;i<=n;++i){if(vis[i])continue;Q.push(pos((double)(deg[i])/sum[i],i));}while(!Q.empty()){while(!Q.empty()&&check[Q.top().now])Q.pop();if(Q.empty())break;pos tmp=Q.top();if(tmp.k>=k)break;int u=tmp.now;check[u]=true;for(int i=h[u];i;i=G[i].next){int v=G[i].to;if(check[v]||vis[v])continue;deg[v]--;Q.push(pos((double)(deg[v])/sum[v],v));}}if(Q.empty())return false;return true;
}int main(){scanf("%d%d%d",&n,&m,&k);for(int i=1;i<=k;++i){scanf("%d",&x);vis[x]=true;}for(int i=1;i<=m;++i){scanf("%d%d",&u,&v);add(u,v);add(v,u);sum[u]++;sum[v]++;}double L=0,R=1;for(int i=1;i<=50;++i){double mid=(L+R)/2;if(Get_check(mid))L=mid;else R=mid;}Get_check(L);tot=0;for(int i=1;i<=n;++i){if(check[i]||vis[i])continue;ans[++tot]=i;}printf("%d\n",tot);for(int i=1;i<=tot;++i)printf("%d ",ans[i]);return 0;
}