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

#define int LL
using LL = long long;

void solve() {
    int n,m,k;
    cin>>n>>m>>k;
    vector<bool> flag(n+1);
    for(int i=0;i<k;i++) {
        int _;
        cin>>_;
        flag[_] = true;
    }
    int p = 1;
    while(p<=n && flag[p])p++;
    if(p == n+1) {
        cout<<"No"<<endl;
        return ;
    }
    vector<vector<int> >G(n+1);
    for(int i=0;i<m;i++) {
        int u,v;
        cin>>u>>v;
        G[u].push_back(v);
        G[v].push_back(u);
    }
    queue<pair<int,int> > que;
    que.push({-1,p});
    vector<pair<int,int>> res;
    vector<bool> visited(n+1);
    while(!que.empty()) {
        auto [fa,to] = que.front();
        que.pop();
        if(visited[to])continue;
        visited[to] = true;
        res.push_back({fa,to});
        if(flag[to])continue;
        for(int i=0;i<G[to].size();i++) {
            que.push({to,G[to][i]});
        }
    }
    if(res.size() != n) {
        cout<<"No"<<endl;
        return ;
    }
    cout<<"Yes"<<endl;
    cout<<n-1<<endl;
    for(int i=1;i<res.size();i++) {
        cout<<res[i].first<<' '<<1<<' '<<res[i].second<<endl;
    }
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }
}