Codeforces Round 368 (Div. 2)
B
Bakery
Codeforces
1300
原题
← AC →
翻译中…

Masha wants to open her own bakery and bake muffins in one of the $*n*$ cities numbered from $1$ to $*n*$. There are $*m*$ bidirectional roads, each of whose connects some pair of cities.

翻译中…

To bake muffins in her bakery, Masha needs to establish flour supply from some storage. There are only $*k*$ storages, located in different cities numbered $*a*_{1}, *a*_{2}, ..., *a*_{*k*}$.

翻译中…

Unforunately the law of the country Masha lives in prohibits opening bakery in any of the cities which has storage located in it. She can open it only in one of another $*n* - *k*$ cities, and, of course, flour delivery should be paid — for every kilometer of path between storage and bakery Masha should pay $1$ ruble.

翻译中…

Formally, Masha will pay $*x*$ roubles, if she will open the bakery in some city $*b*$ ($*a*_{*i*} ≠ *b*$ for every $1 ≤ *i* ≤ *k*$) and choose a storage in some city $*s*$ ($*s* = *a*_{*j*}$ for some $1 ≤ *j* ≤ *k*$) and $*b*$ and $*s*$ are connected by some path of roads of summary length $*x*$ (if there are more than one path, Masha is able to choose which of them should be used).

翻译中…

Masha is very thrifty and rational. She is interested in a city, where she can open her bakery (and choose one of $*k*$ storages and one of the paths between city with bakery and city with storage) and pay minimum possible amount of rubles for flour delivery. Please help Masha find this amount.

翻译中…

Input

翻译中…

The first line of the input contains three integers $*n*$, $*m*$ and $*k*$ ($1 ≤ *n*, *m* ≤ 10^{5}$, $0 ≤ *k* ≤ *n*$) — the number of cities in country Masha lives in, the number of roads between them and the number of flour storages respectively.

翻译中…

Then $*m*$ lines follow. Each of them contains three integers $*u*$, $*v*$ and $*l*$ ($1 ≤ *u*, *v* ≤ *n*$, $1 ≤ *l* ≤ 10^{9}$, $*u* ≠ *v*$) meaning that there is a road between cities $*u*$ and $*v*$ of length of $*l*$ kilometers .

翻译中…

If $*k* > 0$, then the last line of the input contains $*k*$ distinct integers $*a*_{1}, *a*_{2}, ..., *a*_{*k*}$ ($1 ≤ *a*_{*i*} ≤ *n*$) — the number of cities having flour storage located in. If $*k* = 0$ then this line is not presented in the input.

翻译中…

Output

翻译中…

Print the minimum possible amount of rubles Masha should pay for flour delivery in the only line.

翻译中…

If the bakery can not be opened (while satisfying conditions) in any of the $*n*$ cities, print $- 1$ in the only line.

翻译中…

Note

翻译中…

imageImage illustrates the first sample case. Cities with storage located in and the road representing the answer are darkened.

翻译中…

样例

Input #1
5 4 2
1 2 5
1 2 3
2 3 4
1 4 10
1 5
Output #1
3
InputCopy OutputCopy
Input #2
3 1 1
1 2 3
3
Output #2
-1
InputCopy OutputCopy
题目信息
题号
707B
时间限制
2 s
内存限制
256 MB
标签
图论

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。