#D783. Bear and Tree Jumps
Bear and Tree Jumps
Bear and Tree Jumps
A tree is an undirected connected graph without cycles. The distance between two vertices is the number of edges in a simple path between them.
Limak is a little polar bear. He lives in a tree that consists of n vertices, numbered 1 through n.
Limak recently learned how to jump. He can jump from a vertex to any vertex within distance at most k.
For a pair of vertices (s, t) we define f(s, t) as the minimum number of jumps Limak needs to get from s to t. Your task is to find the sum of f(s, t) over all pairs of vertices (s, t) such that s < t.
Input
The first line of the input contains two integers n and k (2 ≤ n ≤ 200 000, 1 ≤ k ≤ 5) — the number of vertices in the tree and the maximum allowed jump distance respectively.
The next n - 1 lines describe edges in the tree. The i-th of those lines contains two integers ai and bi (1 ≤ ai, bi ≤ n) — the indices on vertices connected with i-th edge.
It's guaranteed that the given edges form a tree.
Output
Print one integer, denoting the sum of f(s, t) over all pairs of vertices (s, t) such that s < t.
Examples
Input
6 2 1 2 1 3 2 4 2 5 4 6
Output
20
Input
13 3 1 2 3 2 4 2 5 2 3 6 10 6 6 7 6 13 5 8 5 9 9 11 11 12
Output
114
Input
3 5 2 1 3 1
Output
3
Note
In the first sample, the given tree has 6 vertices and it's displayed on the drawing below. Limak can jump to any vertex within distance at most 2. For example, from the vertex 5 he can jump to any of vertices: 1, 2 and 4 (well, he can also jump to the vertex 5 itself).
There are pairs of vertices (s, t) such that s < t. For 5 of those pairs Limak would need two jumps: (1, 6), (3, 4), (3, 5), (3, 6), (5, 6). For other 10 pairs one jump is enough. So, the answer is 5·2 + 10·1 = 20.
In the third sample, Limak can jump between every two vertices directly. There are 3 pairs of vertices (s < t), so the answer is 3·1 = 3.
inputFormat
Input
The first line of the input contains two integers n and k (2 ≤ n ≤ 200 000, 1 ≤ k ≤ 5) — the number of vertices in the tree and the maximum allowed jump distance respectively.
The next n - 1 lines describe edges in the tree. The i-th of those lines contains two integers ai and bi (1 ≤ ai, bi ≤ n) — the indices on vertices connected with i-th edge.
It's guaranteed that the given edges form a tree.
outputFormat
Output
Print one integer, denoting the sum of f(s, t) over all pairs of vertices (s, t) such that s < t.
Examples
Input
6 2 1 2 1 3 2 4 2 5 4 6
Output
20
Input
13 3 1 2 3 2 4 2 5 2 3 6 10 6 6 7 6 13 5 8 5 9 9 11 11 12
Output
114
Input
3 5 2 1 3 1
Output
3
Note
In the first sample, the given tree has 6 vertices and it's displayed on the drawing below. Limak can jump to any vertex within distance at most 2. For example, from the vertex 5 he can jump to any of vertices: 1, 2 and 4 (well, he can also jump to the vertex 5 itself).
There are pairs of vertices (s, t) such that s < t. For 5 of those pairs Limak would need two jumps: (1, 6), (3, 4), (3, 5), (3, 6), (5, 6). For other 10 pairs one jump is enough. So, the answer is 5·2 + 10·1 = 20.
In the third sample, Limak can jump between every two vertices directly. There are 3 pairs of vertices (s < t), so the answer is 3·1 = 3.
样例
6 2
1 2
1 3
2 4
2 5
4 6
20
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