CF1023G.Pisces

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题目描述

A group of researchers are studying fish population in a natural system of lakes and rivers. The system contains nn lakes connected by n1n - 1 rivers. Each river has integer length (in kilometers) and can be traversed in both directions. It is possible to travel between any pair of lakes by traversing the rivers (that is, the network of lakes and rivers form a tree).

There is an unknown number of indistinguishable fish living in the lakes. On day 11 , fish can be at arbitrary lakes. Fish can travel between lakes by swimming the rivers. Each fish can swim a river ll kilometers long in any direction in ll days. Further, each fish can stay any number of days in any particular lake it visits. No fish ever appear or disappear from the lake system. Each lake can accomodate any number of fish at any time.

The researchers made several observations. The jj -th of these observations is "on day djd_j there were at least fjf_j distinct fish in the lake pjp_j ". Help the researchers in determining the smallest possible total number of fish living in the lake system that doesn't contradict the observations.

输入格式

The first line contains a single integer nn ( 1n1051 \leq n \leq 10^5 ) — the number of lakes in the system.

The next n1n - 1 lines describe the rivers. The ii -th of these lines contains three integers uiu_i , viv_i , lil_i ( 1ui,vin1 \leq u_i, v_i \leq n , uiviu_i \neq v_i , 1li1031 \leq l_i \leq 10^3 ) — 11 -based indices of lakes connected by the ii -th river, and the length of this river.

The next line contains a single integer kk ( 1k1051 \leq k \leq 10^5 ) — the number of observations.

The next kk lines describe the observations. The jj -th of these lines contains three integers djd_j , fjf_j , pjp_j ( 1dj1081 \leq d_j \leq 10^8 , 1fj1041 \leq f_j \leq 10^4 , 1pjn1 \leq p_j \leq n ) — the day, the number of fish, and the lake index of the jj -th observation. No two observations happen on the same day at the same lake simultaneously.

输出格式

Print one integer — the smallest total number of fish not contradicting the observations.

输入输出样例

  • 输入#1

    4
    1 2 1
    1 3 1
    1 4 1
    5
    1 1 2
    1 1 3
    2 2 1
    3 1 4
    3 1 2
    

    输出#1

    2
    
  • 输入#2

    5
    1 2 1
    1 3 1
    1 4 1
    1 5 1
    4
    1 1 2
    2 1 3
    3 1 4
    4 1 5
    

    输出#2

    2
    
  • 输入#3

    5
    2 5 1
    5 1 1
    2 4 1
    5 3 3
    6
    5 2 4
    2 1 1
    2 1 3
    2 2 4
    4 7 5
    4 1 2
    

    输出#3

    10
    

说明/提示

In the first example, there could be one fish swimming through lakes 22 , 11 , and 44 , and the second fish swimming through lakes 33 , 11 , and 22 .

In the second example a single fish can not possibly be part of all observations simultaneously, but two fish swimming 2142 \to 1 \to 4 and 3153 \to 1 \to 5 can.

In the third example one fish can move from lake 11 to lake 55 , others staying in their lakes during all time: two fish in lake 44 , six fish in lake 55 , one fish in lake 33 . The system of lakes is shown on the picture.

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