codeforces #309 D

#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;//?????
	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;
}