SOLVE
LATER
Nick is the mayor of JosephLand. He wants to make a reform of the roads in JosephLand. In JosephLand, there are n cities, numbered 1 through n. There are also m weighted, directed roads represented by three numbers:
Nick is going to have a travel. Travel consists of q journeys. Each journey is represented by two numbers: \(a_i, b_i\). That means, he starts his journey in \(a_i\) and ends in \(b_i\). Every time he will choose a journey with minimum \(cost\). \(Cost\) of a journey is equal to the sum of \(fines\) he paid during the journey.
\(Consumption\) of a travel is \(\sum_{j=1}^{q} cost_j\). As Nick is the mayor of JosephLand, before the travel he can change directions of any roads as many times as he wants. So now Nick wants to change directions of some roads in such a way, that \(consumption\) is minimal. Note that no changes can be made.
Input format
The first line contains two integers n, m — the number of cities and the number of roads, respectively.
Next m lines contain three integers each, \(u_i\), \(v_i\) and \(w_i\) denoting there is a road from \(u_i\) to \(v_i\) and the \(fine\) is \(w_i\). Note that between a pair of cities can exist more than one road.
Next line contains a single integer q — the number of journeys.
Next q lines contain two integers each, \(a_i\) and \(b_i\) — the start and the end of the journey, respectively. Note that the start and the end can be the same city.
It is guaranteed that the JosephLand is connected.
Note: there can be a problem with stack size.
Output format
Print the minimum \(consumption\) that Nick can achieve.
Constraints
Subtasks
We can change directions of first and third roads. The graph will be as follows:
From 6 to 5 there is only path and we don't pay anything, so \(cost_1\) = 0
From 7 to 5 we have to pay \(fine\) for passing the road from 5 to 4, so \(cost_2\) = 10
Overall \(consumption\) =10 and you can not achieve better than this answer!