characterize the distance between two volunteers I and j, dis(i,j) as the number of edges on the most brief way from vertex I to vertex j on the tree. dis(i,j)=0 at whatever point i=j. A portion of the volunteers can go to the on location gathering while others can't. In the event that for some volunteer x and nonnegative
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We characterize the distance between two volunteers I and j, dis(i,j) as the number of edges on the most brief way from vertex I to vertex j on the tree. dis(i,j)=0 at whatever point i=j.
A portion of the volunteers can go to the on location gathering while others can't. In the event that for some volunteer x and nonnegative integer r, all volunteers whose distance to x is close to r can go to the on location gathering, a discussion with span r can happen. The level of the on location get-together is characterized as the greatest conceivable sweep of any discussion that can occur.
Accept that each volunteer can go to the on location gathering with likelihood 12 and these occasions are autonomous. Output the normal level of the on location get-together. At the point when no volunteer can join in, the level is characterized as −1. At the point when everything volunteers can join in, the level is characterized as n.
Input
The principal line contains a solitary integer n (2≤n≤300) meaning the number of volunteers.
Each of the following n−1 lines contains two integers an and b signifying an edge between vertex an and vertex b.
Output
Output the normal level modulo 998244353.
Officially, let M=998244353. It tends to be shown that the appropriate response can be communicated as an unchangeable division pq, where p and q are integers and q≢0(modM). Output the integer equivalent to p⋅q−1modM. All in all, output such an integer x that 0≤x<M and x⋅q≡p(modM).
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