#include <bits/stdc++.h>
#define int long long
using namespace std;
string to_string(string s) { return s; }
template <typename T> string to_string(T v) {
bool first = true;
string res = "[";
for (const auto &x : v) {
if (!first)
res += ", ";
first = false;
res += to_string(x);
}
res += "]";
return res;
}
template <typename A, typename B>
string to_string(pair<A, B> p) {
return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
void dbg_out() { cout << endl; }
template <typename Head, typename... Tail> void dbg_out(Head H, Tail... T) {
cout << ' ' << to_string(H);
dbg_out(T...);
}
#ifdef DEBUG
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif
template <typename T>
using grid = vector<vector<T>>;
template <typename T>
using space = grid<vector<T>>;
using qi = pair<pair<int, int>, pair<int, int>>;
template <typename T>
using lpq = priority_queue<T, vector<T>, less<T>>;
using idata = vector<int>;
using graph = grid<pair<int, int>>;
graph roads;
idata path;
struct State {
int source = -1, distance = 1e18, count = 0;
State next (int cost, int curr, int target) {
State res;
res.source = curr;
res.distance = target == source ? 1e18 : cost + distance;
res.count = count + 1 < path.size() && target == path[count + 1] ? count + 1 : count;
return res;
}
};
int N, M, T, L;
int modify (vector<State> &states, State new_state) {
if (states[0].source == new_state.source) {
if (new_state.distance >= states[0].distance) return -1;
states[0].distance = new_state.distance;
return 0;
} else if (states[0].distance >= new_state.distance) {
states[1] = states[0];
states[0] = new_state;
return 0;
} else if (states[1].source == new_state.source) {
if (new_state.distance >= states[1].distance) return -1;
states[1].distance = new_state.distance;
return 1;
} else if (states[1].distance > new_state.distance) {
states[1] = new_state;
return 1;
}
return -1;
}
int dijkstra () {
space<State> dij_state (N, grid<State>(L, vector<State>(2)));
lpq<qi> q;
dij_state[path[0]][0][0].distance = 0;
q.push({ { 0, 0 }, { path[0], 0 } });
while (q.size() != 0) {
qi data = q.top(); q.pop();
int dist = data.first.first;
int src = data.first.second;
int curr = data.second.first;
int uuid = data.second.second;
if (dist == 1e18) continue ;
State st = dij_state[curr][src][uuid];
if (st.distance != dist) continue ;
for (const auto &road : roads[curr]) {
int next = road.first; int cost = road.second;
State nxt_state = st.next( cost, curr, next );
int res = modify(dij_state[next][nxt_state.count], nxt_state);
if (res == -1) continue ;
q.push({ { nxt_state.distance, nxt_state.count }, { next, res } });
}
}
int res = dij_state[path[L - 1]][L - 1][0].distance;
return res == 1e18 ? -1 : res;
}
signed main () {
cin >> N >> M >> T >> L;
roads.resize(N);
for (int i = 0; i < M; i ++) {
int a, b, c;
cin >> a >> b >> c;
a --; b --;
roads[a].push_back({ b, c });
roads[b].push_back({ a, c });
}
path.resize(L);
for (int i = 0; i < L; i ++) {
cin >> path[i];
path[i] --;
}
for (int i = 0; i < T; i ++) {
int p, v;
cin >> p >> v;
p --; v --;
path[p] = v;
cout << dijkstra() << "\n";
}
}
