JOI '17 Final P4 - Commuter Pass

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Points: 15
Time limit: 1.0s
Memory limit: 512M

Problem type

JOI-kun is living in a city with N stations. The stations are numbered from 1 to N. There are M railways numbered from 1 to M. The railway i (1iM) connects the station Ai and the station Bi in both directions, and the fare is Ci yen.

JOI-kun is living near the station S, and goes to the IOI high school near the station T. He is planning to buy a commuter pass connecting these two stations. When he buys a commuter pass, he needs to choose a route between the station S and the station T with minimum cost. Using this commuter pass, he can take any railway contained in a chosen route in any direction without additional costs.

JOI-kun often goes to bookstores near the station U and the station V. Therefore, he wants to buy a commuter pass so that the cost from the station U to the station V is minimized. When he moves from the station U to the station V, he first chooses a route from the station U to the station V. Then the fare he has to pay is

  • 0 yen if the railway i is contained in a route chosen when he buys a commuter pass, or
  • Ci yen if the railway i is not contained in a route chosen when he buys a commuter pass.

The sum of the above fare is the cost from the station U to the station V. He wants to know the minimum cost from the station U to the station V if he chooses a route appropriately when he buys a commuter pass.

Input Specification

The first line of input contains two space separated integers N, M. This means the city JOI-kun lives in has N stations and M railways.

The second line contains two space separated integers S, T (ST). This means JOI-kun is planning to buy a commuter pass from the station S to the station T.

The third line contains two space separated integers U, V (UV). This means JOI-kun wants to minimize the cost from the station U to the station V.

Each of the following M lines contains three space separated integers Ai, Bi, Ci (1Ai,BiN, 1Ci109). The railway i connects the station Ai and the station Bi in both directions, and the fare is Ci yen.

Output Specification

Write one line to the standard output. The output should contain the minimum cost from the station U to the station V if he chooses a route appropriately when he buys a commuter pass.

Constraints

In all test cases, 1N105, 1M2×105, SU or TV.

In 16% test cases, S=U.

In another 15% test cases, there is a unique route with minimum cost from the station S to the station T.

In another 24% test cases, N300.

Sample Input 1

Copy
6 6
1 6
1 4
1 2 1
2 3 1
3 5 1
2 4 3
4 5 2
5 6 1

Sample Output 1

Copy
2

Sample Input 2

Copy
8 8
5 7
6 8
1 2 2
2 3 3
3 4 4
1 4 1
1 5 5
2 6 6
3 7 7
4 8 8

Sample Output 2

Copy
15

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