1 # include<cstdio>
  2 # include<iostream>
  3 # include<fstream>
  4 # include<algorithm>
  5 # include<functional>
  6 # include<cstring>
  7 # include<string>
  8 # include<cstdlib>
  9 # include<iomanip>
 10 # include<numeric>
 11 # include<cctype>
 12 # include<cmath>
 13 # include<ctime>
 14 # include<queue>
 15 # include<stack>
 16 # include<list>
 17 # include<set>
 18 # include<map>
 19 
 20 using namespace std;
 21 
 22 const double PI=4.0*atan(1.0);
 23 
 24 typedef long long LL;
 25 typedef unsigned long long ULL;
 26 
 27 # define inf 999999999
 28 # define MAX 123
 29 
 30 int f[MAX];
 31 int n,m;
 32 int sum;
 33 
 34 struct edge
 35 {
 36     int u;
 37     int v;
 38     int w;
 39 }e[10004];
 40 
 41 int cmp ( const struct edge  & a,const struct  edge & b )
 42 {
 43     return a.w < b.w;
 44 }
 45 
 46 void input()
 47 {
 48     for ( int i = 1;i <= m;i++ )
 49     {
 50         int t1,t2,t3;
 51         scanf("%d %d %d",&e[i].u,&e[i].v,&e[i].w);
 52     }
 53 }
 54 
 55 int getf( int v )
 56 {
 57     if ( v==f[v] )
 58     {
 59         return v;
 60     }
 61     else
 62     {
 63         f[v] = getf(f[v]);
 64         return f[v];
 65     }
 66 }
 67 
 68 int merge ( int v,int u )
 69 {
 70     int t1 = getf(v);
 71     int t2 = getf(u);
 72 
 73     if ( t1!=t2 )
 74     {
 75         f[t2] = t1;//t2的祖先是t1
 76         return 1;
 77     }
 78     return 0;
 79 }
 80 
 81 void Kruskal()
 82 {
 83     int cnt = 0;
 84     sort(e+1,e+m+1,cmp);
 85     for ( int i = 1;i <= m;i++ )
 86     {
 87         if ( merge( e[i].u,e[i].v ) )
 88         {
 89             cnt++;
 90             sum+=e[i].w;
 91         }
 92         if ( cnt==n-1)
 93             return;
 94     }
 95 }
 96 
 97 int main(void)
 98 {
 99     while ( scanf("%d",&n)!=EOF )
100     {
101         if ( n==0 )
102             break;
103         memset(e,0,sizeof(e));
104         sum = 0;
105         m = (n-1)*n/2;
106         input();
107 
108         for ( int i = 1;i <= n;i++ )
109         {
110             f[i] = i;
111         }
112         Kruskal();
113         printf("%d\n",sum);
114     }
115 
116     return 0;
117 }