#include <bits/stdc++.h>
using namespace std;

int n,m,a,b,w,v;
int odw[1000006],t[1000006],odleglosc[1000006];
vector <int> G[1000006];
queue <int> q;

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin>>n>>m;

    for(int i = 1; i <= n; i++)
    {
        cin>>t[i];
        if(t[i] == 1)  q.push(i);
    }

    for(int i = 1; i <= m; i++)
    {
        cin>>a>>b;
        G[a].push_back(b);
        G[b].push_back(a);
    }

    while(!q.empty())
    {
        w = q.front();
        q.pop();
        for(int i = 0; i < G[w].size(); i++)
        {
            v = G[w][i];
            if(odw[v] == 0)
            {
                odw[v] = 1;
                q.push(v);
            }
        }
    }



}