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#include<bits/stdc++.h>
using namespace std;

#define rep(i, n) for(int i=0;i<(int)(n);i++)
#define all(X) (X).begin(), (X).end()
#define mp make_pair
#define st first
#define nd second
typedef long long ll;
#define int long long
const ll INF = 1e17;

typedef pair<int,int> pii;

vector<int> calc(vector<vector<int> > vals, int diff) {
    const int n = vals.size();
    vector<int> setup(n);
    vector<set<pair<int,pii>, greater<pair<int,pii> > > > slacks(5);
    const vector<int> diffs = {0,-1,0,1};

    auto vals2 = vals;
    for(auto &a : vals2)
        a[2] = max(a[2], a[0]);

    auto chan = [&](int i, int x) {
        for(int j=1;j<=3;j++)
            slacks[2 + diffs[j] - diffs[setup[i]]].erase({vals2[i][j]-vals2[i][setup[i]],{i,j}});

        setup[i] = x;
        for(int j=1;j<=3;j++)
            slacks[2 + diffs[j] - diffs[setup[i]]].insert({vals2[i][j]-vals2[i][setup[i]],{i,j}});
    };


    for(int i=0;i<n;i++) {
        if(i == 0) {
            setup[i] = diff+2;
        }
        else
            setup[i] = 2;
        for(int j=1;j<=3;j++)
            slacks[2 + diffs[j] - diffs[setup[i]]].insert({vals2[i][j]-vals2[i][setup[i]],{i,j}});
    }

    bool nfound = 1;
    do {
        nfound = 1;
        for(int C=0;nfound && C<5;C++) {
            auto it = slacks[C].begin();
            if(it == slacks[C].end()) continue;
                
            int i = it->nd.st;
            for(int s=0;nfound && s<5;s++) {
                int t = 6-C-s;
                if(t < 0 || t >= 5) continue;
                const auto& sls = slacks[s];
                const auto& slt = slacks[t];
                auto itj = sls.begin();
                while(itj != sls.end() && itj->nd.st == i)
                    itj++;
                if(itj == sls.end())
                    continue;
                int j = itj->nd.st;

                auto itk = slt.begin();
                while(itk != slt.end() && (itk->nd.st == i || itk->nd.st == j))
                    itk++;
                if(itk == slt.end())
                    continue;
                int k = itk->nd.st;

                vector<pii> lst = {{i,it->nd.nd}, {j, itj->nd.nd}, {k,itk->nd.nd}};
                if(it->st + itj->st + itk->st > 0) {
                    for(auto a:lst)
                        chan(a.st, a.nd);
                    nfound = 0;
                }
            }
        }
    }while(nfound == 0);

    for(int i=0;i<n;i++)
        if(setup[i] == 2)
            if(vals[i][0] == vals2[i][2])
                setup[i] = 0;

    return setup;
}

int getScoreAndFixIfWrongParity(int reqParity, const vector<int>& setup, const vector<vector<int> >& vals) {
    const int n = setup.size();
    vector<vector<vector<pii> > > swapsL(4,vector<vector<pii> >(4,vector<pii>(1,{INF,-1})));
    int score = 0;
    for(int i=0;i<n;i++) {
        score += vals[i][setup[i]];
        for(int j=0;j<4;j++)
            swapsL[setup[i]][j].push_back({vals[i][setup[i]] - vals[i][j], i});
    }

    for(int i=0;i<4;i++)
        for(int j=0;j<4;j++)
            sort(all(swapsL[i][j]));
        
    auto route = [&](const vector<int>& a) {
        set<int> used;
        int res = 0;
        for(int i=0;i<a.size();i+=2) {
            const auto& sl = swapsL[a[i]][a[i+1]];
            int x = 0;
            while(used.count(sl[x].nd)) x++;

            if(sl[x].nd != -1)
                used.insert(sl[x].nd);
            if(res >= INF)
                return res;
            res += sl[x].st;
        }
        return res;
    };

    //<3
    if(count(all(setup), 2)%2 != reqParity) {
        return score -= min({route({0,2}), route({2,0}),
            route({1,2,3,0}), route({3,2,1,0}),
            route({2,3,3,0}), route({2,1,1,0}), route({0,3,3,2}), route({0,1,1,2}),
            route({0,1,2,3}), route({0,3,2,1}),
            route({0,1,1,3,2,1}), route({0,3,3,1,2,3}),
            route({2,1,0,3}), route({2,3,0,1}),
            route({2,1,1,3,0,1}), route({2,3,3,1,0,3}),

            route({2,1,1,3,3,0}), route({2,3,3,1,1,0}),
            route({0,1,1,3,3,2}), route({0,3,3,1,1,2}),
            
            route({1,2,3,1,1,0}), route({1,0,1,2,3,1}),
            route({3,2,1,3,3,0}), route({3,0,3,2,1,3}),
            route({3,0,3,2,1,3}), route({3,2,3,0,1,3}),
            route({1,0,1,2,3,1}), route({1,2,1,0,3,1}),      
        });
    }
    return score;
}

vector<int> combine(vector<vector<int> > vals) {
    vector<vector<int> > res = {calc(vals,0), calc(vals,-1), {}, calc(vals,1)};
    res[2] = res[0];

    return {
        getScoreAndFixIfWrongParity(0, res[0], vals),
        getScoreAndFixIfWrongParity(0, res[1], vals),
        getScoreAndFixIfWrongParity(1, res[2], vals),
        getScoreAndFixIfWrongParity(0, res[3], vals),
    };
}

vector<vector<pii> > graf;

vector<int> combineValsViaDp(vector<vector<int> > vals) {
    const int n = vals.size();
    function<int(int,int)> dpsolv = [&](int diff, int b)->int {
        vector<vector<int> > dp(n+1,vector<int>(2*n+1,-INF));
        vector<vector<int> > dp2(n+1,vector<int>(2*n+1,-INF));
        dp[0][n] = 0;
        for(int i=0;i<n;i++) {
            for(int j=0;j<2*n+1;j++) {
                dp[i+1][j] = dp[i][j] + vals[i][0];
                dp[i+1][j] = max(dp[i+1][j], dp2[i][j] + vals[i][2]);
                if(j+1 < dp[i].size())
                    dp[i+1][j] = max(dp[i+1][j], dp[i][j+1] + vals[i][1]);
                if(j-1 >= 0)
                    dp[i+1][j] = max(dp[i+1][j], dp[i][j-1] + vals[i][3]);

                dp2[i+1][j] = dp2[i][j] + vals[i][0];
                dp2[i+1][j] = max(dp2[i+1][j], dp[i][j] + vals[i][2]);
                if(j+1 < dp2[i].size())
                    dp2[i+1][j] = max(dp2[i+1][j], dp2[i][j+1] + vals[i][1]);
                if(j-1 >= 0)
                    dp2[i+1][j] = max(dp2[i+1][j], dp2[i][j-1] + vals[i][3]);
            }
        }
        if(n+diff < 0 ||  n+diff >= dp[0].size())
            return -INF;
        if(b)
            return dp2[n][n+diff];
        return dp[n][n+diff];
    };
    vector<int> res = {dpsolv(0,0), dpsolv(-1,0), dpsolv(0,1), dpsolv(1,0)};
    return res;
}

vector<int> dfs(int cur, int p) {
    vector<vector<int> > vals;
    for(auto a:graf[cur]) if(a.st != p) {
        auto dp = dfs(a.st,cur);
        auto dpUp = {max(dp[3]+a.nd, dp[0]), dp[0]+a.nd, dp[1]+a.nd, dp[2]+a.nd};
        vals.push_back(dpUp);
    }
    if(vals.size() <= 10)
        return combineValsViaDp(vals);
    return combine(vals);
}

int32_t main(){
    ios::sync_with_stdio(false);
    srand(10494);
    cin.tie(0);
    int n;
    cin >> n;
    graf.resize(n);
    for(int i=0;i<n-1;i++){
        int a,b,c;
        cin >> a >> b >> c;
        graf[a-1].push_back({b-1,c});
        graf[b-1].push_back({a-1,c});
    } 
    for(auto &a: graf)
        random_shuffle(a.begin(), a.end());
    cout<<dfs(n-1,-1)[0]<<"\n";
}