题目链接：这里
题意：给你一棵树，让你选择两条不相交的路径，使得长度的乘积最大。
解法：枚举删除哪条边，然后再跑树形dp就好了。(维护最长和次长就可以了)

//CF 14D

#include <bits/stdc++.h>
using namespace std;
const int maxn = 206;
vector <int> G[maxn];
int n, maxlen;
int dfs(int x, int fa){
    int len1 = 0, len2 = 0, len = 0;
    for(int i = 0; i < G[x].size(); i++){
        int v = G[x][i];
        if(v == fa) continue;
        len = max(dfs(v, x), len);
        if(maxlen > len1){
            len2 = len1;
            len1 = maxlen;
        }
        else{
            len2 = max(len2, maxlen);
        }
    }
    len = max(len, len1+len2);
    maxlen = len1 + 1;
    return len;
}
int main()
{
    scanf("%d", &n);
    for(int i = 1; i < n; i++){
        int u, v;
        scanf("%d%d", &u, &v);
        G[u].push_back(v);
        G[v].push_back(u);
    }
    int ans = 0;
    for(int i = 1; i <= n; i++){
        for(int j = 0; j < G[i].size(); j++){
            int a = dfs(G[i][j], i);
            int b = dfs(i, G[i][j]);
            ans = max(ans, a*b);
        }
    }
    cout << ans << endl;
    return 0;
}