A long time ago in a galaxy far, far away, there are N planets
numbered from 1 to N.
Each planet has M cities numbered from 1
to M. Let city f of planet e be denoted as (e,f).
There are N × P two-way flights in the galaxy. For every planet e (1 ≤ e ≤ N), there are P flights
numbered from 1 to P.
Flight i connects cities (e,ai) and
(e,bi)
and costs ci energy daily to maintain.
There are M × Q two-way portals in the galaxy. For all cities with number f (1 ≤ f ≤ M), there are Q portals
numbered from 1 to Q.
Portal j connects cities (xj,f) and
(yj,f)
and costs zj energy daily to maintain.
It is possible to travel between any two cities in the
galaxy using only flights and/or portals.
Hard times have fallen on the galaxy. It was decided
that some flights and/or portals should be shut down to save as much energy as
possible, but it should remain possible to travel between any two cities
afterwards.
What is the maximum sum of energy that can be saved
daily?
The first line contains four space-separated integers N, M, P, Q (1 ≤ N,M,P,Q ≤ 105).
Then P lines follow; the i-th one contains three
space-separated integers ai, bi, ci (1 ≤ ai,bi ≤ M,1 ≤ ci ≤ 108).
Then Q lines follow; the j-th one contains three
space-separated integers xj, yj, zj (1 ≤ xj,yj ≤ N,1 ≤ zj ≤ 108).
It is guaranteed that it will be possible to travel
between any two cities using flights and/or portals. There may be multiple
flights/portals between the same pair of cities or a flight/portal between a
city and itself.
For 2 of the 15 available marks, P,Q ≤ 100 and ci = 1 for
all 1 ≤ i ≤ P, and zj = 1 for all 1 ≤ j ≤ Q.
For an additional 2 of the 15 available marks, P,Q ≤ 200.
For an additional 5 of the 15 available marks, N,M ≤ 200.
Output a single integer, the maximum sum of energy
that can be saved daily.
2 3 4 1
2 3 5
3 2 7
1 2 6
1 1 8
2 1 5
41
One possible way is to shut down the flights between
cities (1,1) and
(1,1),
(2,1) and
(2,1),
(1,1) and
(1,2),
(1,3) and
(1,2),
(2,3) and
(2,2),
and shut down the portal between cities (2,3) and (1,3) for
total energy savings of 8+8+6+7+7+5 = 41.