#include <bits/stdc++.h>

#ifdef DEBUG
#include <Mylib/Debug/debug.cpp>
#else
#define dump(...)
#endif

/**
 * @title グラフ用テンプレート
 * @docs graph_template.md
 */
template <typename Cost = int> class Edge{
public:
  int from,to;
  Cost cost;
  Edge() {}
  Edge(int to, Cost cost): to(to), cost(cost){}
  Edge(int from, int to, Cost cost): from(from), to(to), cost(cost){}
};

template <typename T> using Graph = std::vector<std::vector<Edge<T>>>;
template <typename T> using Tree = std::vector<std::vector<Edge<T>>>;

template <typename T, typename C> void add_edge(C &g, int from, int to, T w = 1){
  g[from].emplace_back(from, to, w);
}

template <typename T, typename C> void add_undirected(C &g, int a, int b, T w = 1){
  add_edge<T, C>(g, a, b, w);
  add_edge<T, C>(g, b, a, w);
}




/**
 * @docs input_tuple_vector.md
 */
template <typename T, size_t ... I>
void input_tuple_vector_init(T &val, int N, std::index_sequence<I...>){
  (void)std::initializer_list<int>{
    (void(std::get<I>(val).resize(N)), 0)...
      };
}

template <typename T, size_t ... I>
void input_tuple_vector_helper(T &val, int i, std::index_sequence<I...>){
  (void)std::initializer_list<int>{
    (void(std::cin >> std::get<I>(val)[i]), 0)...
      };
}

template <typename ... Args>
auto input_tuple_vector(int N){
  std::tuple<std::vector<Args>...> ret;

  input_tuple_vector_init(ret, N, std::make_index_sequence<sizeof...(Args)>());
  for(int i = 0; i < N; ++i){
    input_tuple_vector_helper(ret, i, std::make_index_sequence<sizeof...(Args)>());
  }

  return ret;
}


template <typename T>
struct YenAlgorithm{

  Graph<T> g;
  int s, t, K, N;

  std::vector<std::vector<bool>> valid;

  using Path = std::pair<T, std::vector<int>>;

  std::vector<std::optional<Path>> result;
  std::priority_queue<Path, std::vector<Path>, std::greater<Path>> stock;
  
  YenAlgorithm(Graph<T> g, int s, int t, int K): g(g), s(s), t(t), K(K), N(g.size()){run();}

  void run(){
    valid.resize(N);
    for(int i = 0; i < N; ++i){
      valid[i].assign(g[i].size(), true);
    }

    result.resize(K);

    for(int i = 0; i < K; ++i){
      if(i == 0){
        auto res = shortest_path(s);
        if(res){
          stock.push(*res);
        }
      }else{
        std::vector<int> prev_path;

        {
          int cur = s;
          for(auto u : result[i-1].value().second){
            prev_path.push_back(cur);
            cur = g[cur][u].to;
          }
          prev_path.push_back(t);
          dump(prev_path);
        }

        std::vector<bool> check(i, true);

        for(int k = 0; k < (int)prev_path.size() - 1; ++k){
          const int u = prev_path[k];
          
          for(int j = 0; j < i; ++j){
            if(check[j]){
              valid[prev_path[k]][(*result[j]).second[k]] = false;
            }
          }

          dump(check, valid[prev_path[k]]);

          auto res = shortest_path(u);
          //dump(res);
          if(res){

            auto [c, p] = *res;

            std::vector<int> temp;
            for(int j = 0; j < k; ++j){
              int v = (*result[i-1]).second[j];

              c += g[prev_path[j]][v].cost;
              temp.push_back(v);
            }

            temp.insert(temp.end(), p.begin(), p.end());
            //std::swap(temp, p);
            dump(std::make_pair(c, temp));
            
            stock.emplace(c, temp);
          }
          

          for(int j = 0; j < i; ++j){
            if(check[j]){
              valid[prev_path[k]][(*result[j]).second[k]] = true;
            }
          }

          for(int j = 0; j < i; ++j){
            if(check[j]){
              if(prev_path[k+1] != g[prev_path[k]][(*result[j]).second[k]].to){
                check[j] = false;
              }
            }
          }
        }
      }

      std::cerr << "\n";

      if(stock.empty()) break;

      result[i] = stock.top(); stock.pop();

      while(not stock.empty() and stock.top() == result[i]){
        stock.pop();
      }
    }
  }


  std::optional<std::pair<T, std::vector<int>>> shortest_path(int from){
    std::vector<bool> visited(N, false);
    std::vector<std::optional<T>> dist(N);
    std::vector<std::pair<int, int>> restore(N);

    std::priority_queue<
      std::pair<T, int>,
      std::vector<std::pair<T, int>>,
      std::greater<std::pair<T, int>>> pq;

    dist[from] = 0;
    pq.emplace(0, from);

    while(not pq.empty()){
      auto [d, i] = pq.top(); pq.pop();

      if(visited[i]) continue;
      visited[i] = true;

      for(int k = 0; k < (int)g[i].size(); ++k){
        if(not valid[i][k]) continue;
        auto &e = g[i][k];

        if(not dist[e.to]){
          dist[e.to] = d + e.cost;
          pq.emplace(*dist[e.to], e.to);
          restore[e.to] = std::make_pair(i, k);
        }else{
          if(*dist[e.to] > d + e.cost){
            dist[e.to] = d + e.cost;
            if(not visited[e.to]) pq.emplace(*dist[e.to], e.to);
            restore[e.to] = std::make_pair(i, k);
          }
        }
      }
    }
    
    if(dist[t]){
      std::vector<int> p;

      int cur = t;
      while(cur != from){
        auto [i, j] = restore[cur];
        p.push_back(j);
        cur = i;
      }
      
      std::reverse(p.begin(), p.end());

      return {std::make_pair(*dist[t], p)};
    }else{
      return {}; 
    }
  }
};




int main(){
  int N, M, K; std::cin >> N >> M >> K;
  int X, Y; std::cin >> X >> Y;
  --X, --Y;

  auto [p, q] = input_tuple_vector<long double, long double>(N);

  Graph<long double> g(N);
  for(int i = 0; i < M; ++i){
    int P, Q; std::cin >> P >> Q;
    --P, --Q;

    long double dx = p[P] - p[Q];
    long double dy = q[P] - q[Q];

    long double L = std::sqrt(dx * dx + dy * dy);

    add_undirected(g, P, Q, L);
  }


  auto res = YenAlgorithm(g, X, Y, K).result;

  /*
  std::cerr << "\n";
  
  for(auto a : res){
    std::vector<int> p;
    int cur = X;
    for(auto u : a->second){
      p.push_back(cur);
      cur = g[cur][u].to;
    }
    p.push_back(Y);
    dump(p);
  }

  dump(res);*/

  for(auto x : res){
    if(not x){
      std::cout << -1 << "\n";
    }else{
      std::cout << std::fixed << std::setprecision(12) << x->first << "\n";
    }
  }

  return 0;
}