#include<bits/stdc++.h>

 using namespace std;

 typedef long long ll;

 const int maxn =  + ;

 const int INF = 1e9 + ;

 int Map[maxn][maxn];

 int lowcost[maxn], mst[maxn];

 int n, m;

 void prim(int u)

 {

     ll ans = ;

     for(int i = ; i <= n; i++)

     {

         lowcost[i] = Map[u][i];

         mst[i] = u;

     }

     mst[u] = -;

     for(int i = ; i <= n; i++)

     {

         int minn = INF;

         int v = -;

         //寻找lowcost数组里面的未加入mst的最小值

         for(int j = ; j <= n; j++)

         {

             if(mst[j] != - && lowcost[j] < minn)

             {

                 v = j;

                 minn = lowcost[j];

             }

         }

         if(v != -)

         {

             mst[v] = -;

             ans += lowcost[v];

             for(int j = ; j <= n; j++)

             {

                 if(mst[j] != - && lowcost[j] > Map[v][j])

                 {

                     lowcost[j] = Map[v][j];

                     mst[j] = v;

                 }

             }

         }

     }

     printf("%lld\n", ans);

 }

 int main()

 {

     while(scanf("%d", &n) != EOF && n)

     {

         m = n * (n - ) / ;

         int u, v, w;

         memset(Map, , sizeof(Map));

         memset(lowcost, , sizeof(lowcost));

         while(m--)

         {

             scanf("%d%d%d", &u, &v, &w);

             Map[u][v] = Map[v][u] = w;

         }

         prim();

     }

     return ;

 }