Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.

No tag edit access

D. Exploration plan

time limit per test

2 secondsmemory limit per test

256 megabytesinput

standard inputoutput

standard outputThe competitors of Bubble Cup X gathered after the competition and discussed what is the best way to get to know the host country and its cities.

After exploring the map of Serbia for a while, the competitors came up with the following facts: the country has *V* cities which are indexed with numbers from 1 to *V*, and there are *E* bi-directional roads that connect the cites. Each road has a weight (the time needed to cross that road). There are *N* teams at the Bubble Cup and the competitors came up with the following plan: each of the *N* teams will start their journey in one of the *V* cities, and some of the teams share the starting position.

They want to find the shortest time *T*, such that every team can move in these *T* minutes, and the number of different cities they end up in is at least *K* (because they will only get to know the cities they end up in). A team doesn't have to be on the move all the time, if they like it in a particular city, they can stay there and wait for the time to pass.

Please help the competitors to determine the shortest time *T* so it's possible for them to end up in at least *K* different cities or print -1 if that is impossible no matter how they move.

Note that there can exist multiple roads between some cities.

Input

The first line contains four integers: *V*, *E*, *N* and *K* (1 ≤ *V* ≤ 600, 1 ≤ *E* ≤ 20000, 1 ≤ *N* ≤ *min*(*V*, 200), 1 ≤ *K* ≤ *N*), number of cities, number of roads, number of teams and the smallest number of different cities they need to end up in, respectively.

The second line contains *N* integers, the cities where the teams start their journey.

Next *E* lines contain information about the roads in following format: *A*_{i} *B*_{i} *T*_{i} (1 ≤ *A*_{i}, *B*_{i} ≤ *V*, 1 ≤ *T*_{i} ≤ 10000), which means that there is a road connecting cities *A*_{i} and *B*_{i}, and you need *T*_{i} minutes to cross that road.

Output

Output a single integer that represents the minimal time the teams can move for, such that they end up in at least *K* different cities or output -1 if there is no solution.

If the solution exists, result will be no greater than 1731311.

Example

Input

6 7 5 4

5 5 2 2 5

1 3 3

1 5 2

1 6 5

2 5 4

2 6 7

3 4 11

3 5 3

Output

3

Note

Three teams start from city 5, and two teams start from city 2. If they agree to move for 3 minutes, one possible situation would be the following: Two teams in city 2, one team in city 5, one team in city 3 , and one team in city 1. And we see that there are four different cities the teams end their journey at.

Codeforces (c) Copyright 2010-2020 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: Apr/03/2020 21:28:20 (f3).

Desktop version, switch to mobile version.

Supported by

User lists

Name |
---|