//--------------------------------------------AC code--------------------------------------------//

#include<cstdio>
#include<cstring>

using namespace std;

typedef long long LL;

const int MAXN = 2005;
int n, u, v, p, mark;
LL ans = 1e15, res;

struct Edge{
    int nxt, to, dis;
}edge[MAXN<<1];

int head[MAXN], edge_num;
void add_edge(int from, int to, int dis){
    edge[++edge_num].nxt = head[from];
    edge[edge_num].to = to;
    edge[edge_num].dis = dis;
    head[from] = edge_num;
}

bool vis[MAXN];
void dfs(int x, int f, LL d, int no){
    vis[x] = 1;
    if(d > res){
        res = d;
        mark = x;
    }
    for(int i = head[x]; i; i = edge[i].nxt){
        if(i == no || i == no+1 || edge[i].to == f || vis[edge[i].to])  continue;
        dfs(edge[i].to, x, d+1ll*edge[i].dis, no);
    }
}

int main(){
//  freopen("foodshop.in", "r", stdin);
//  freopen("foodshop.out", "w", stdout);
    scanf("%d", &n);
    for(int i = 1; i <= n; i++){
        scanf("%d%d%d", &u, &v, &p);
        add_edge(u, v, p);
        add_edge(v, u, p);
    }
    for(int i = 1; i <= edge_num; i+=2){
        bool f = true;
        memset(vis, 0, sizeof vis);
        res = mark = 0;
        dfs(1, 0, 0, i);
        for(int j = 1; j <= n; j++)
            if(!vis[j]){
                f = false;
                break;
            }
        if(!f)  continue;
        memset(vis, 0, sizeof vis);
        res = 0;
        dfs(mark, 0, 0, i);
        if(ans > res)   ans = res;
    }
    printf("%.1lf", (double)ans * 0.5);
    return 0;
}