#include <cstdio>

#include <cstring>

#include <iostream>

#include <algorithm>

using namespace std;

const int MAX_N =  + ;

int u[MAX_N], v[MAX_N], w[MAX_N];

int p[MAX_N], r[MAX_N];

inline int cmp(const int i, const int j) { return w[i] < w[j]; }

int Find(int a)

{

    if (p[a] == a)

        return a;

    else

        return p[a] = Find(p[a]);

}

int Union(int a, int b)

{

    int p_a = Find(a);

    int p_b = Find(b);

    if (p_a == p_b)

        return -;

    if (p_a > p_b)

        p[p_b] = p_a;

    else

        p[p_a] = p_b;

    return ;

}

inline int Kruskal(int road_num)

{

    int ans = ;

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

        p[i] = i;

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

        r[i] = i;

    sort(r, r + road_num, cmp);

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

    {

        int e = r[i];

        int x = Find(u[e]);

        int y = Find(v[e]);

        if (x != y)

        {

            ans += w[e];

            Union(x, y);

        }

    }

    return ans;

}

int main()

{

    int ver_num;

    int ver_1, ver_2, len;

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

    {

        int road_num = ver_num * (ver_num - ) / ;

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

        {

            scanf("%d %d %d", &ver_1, &ver_2, &len);

            u[i] = ver_1;

            v[i] = ver_2;

            w[i] = len;

        }

        int ans = Kruskal(road_num);

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

    }

    return ;

}