#include <map>
#include <set>
#include <list>
#include <array>
#include <cmath>
#include <deque>
#include <queue>
#include <stack>
#include <tuple>
#include <bitset>
#include <cfloat>
#include <memory>
#include <vector>
#include <random>
#include <string>
#include <cassert>
#include <climits>
#include <cstring>
#include <iomanip>
#include <numeric>
#include <iostream>
#include <algorithm>
#include <functional>
#include <unordered_map>
#include <unordered_set>

#define rep(i, s, e) for (int i = s; i <= e; ++i)
#define per(i, s, e) for (int i = s; i >= e; --i)

using i64 = long long;

using namespace std;

const int N = 2e5 + 10;

int n, m, k, dep[N], pre[N];
bool tag[N], vis[N];
vector <int> e[N], o;

void dfs(int u) {
  if (vis[u]) return;
  vis[u] = true;
  o.emplace_back(u);
  if (!tag[u]) {
    for (int v : e[u]) {
      if (!vis[v]) {
        dep[v] = dep[u] + 1, pre[v] = u;
        dfs(v);
      }
    }
  }
}

void solve() {
  cin >> n >> m >> k;
  rep(i, 1, n) pre[i] = 0, tag[i] = false, e[i].clear();
  rep(i, 1, k) {
    int x;
    cin >> x;
    tag[x] = true;
  }
  rep(i, 1, m) {
    int u, v;
    cin >> u >> v;
    e[u].emplace_back(v);
    e[v].emplace_back(u);
  }
  o.clear();
  rep(i, 1, n) if (!tag[i]) {
    dfs(i);
    break;
  }
  if (o.size() < n) {
    printf("No\n");
    return;
  }
  printf("Yes\n");
  printf("%d\n", n - 1);
  for (int i = 1; i < n; ++i) {
    printf("%d 1 %d\n", pre[o[i]], o[i]);
  }
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0), cout.tie(0);
  int tc = 1;
  while (tc--) solve();
  return 0;
}