#include<stdio.h>
#include<string.h>
#define max 99999
int map[101][101],visit[101],lowcost[101];
int temp,n;
int prime()
{
int i,j,k,sum=0;
memset(visit,0,sizeof(visit));
visit[1] = 1;
for(i = 1; i <= n; i++)
lowcost[i] = map[1][i];
for(i = 1; i <= n; i++)
{
temp = max;
for(j = 1; j <= n; j++)
{
if(!visit[j] && lowcost[j] < temp)
{
k=j;
temp = lowcost[k];
}
}
if(temp == max)
break;
sum += temp;
visit[k]=1;
for(j = 1; j <= n; j++)
if(!visit[j] && lowcost[j] > map[k][j])
lowcost[j]=map[k][j];
}
return sum;
}
int main()
{
int i,m,a,b,cost,min;
while(scanf("%d",&n)==1 && n)
{
m = n * (n-1) / 2;
temp = max;
memset(map,max,sizeof(map));
for(i = 1; i <= m; i++)
{
scanf("%d %d %d",&a,&b,&cost);
if(cost<temp)
map[a][b] = map[b][a] = cost;
}
min = prime();
printf("%d\n",min);
}
return 0;
}