> #include<stdio.h>
> #include<stdlib.h>
> 
> const int MAX =0x7fffffff;
> int lowcost[110];
> int g[110][110];
> int visited[110];
> 
> void init(int n)
> {
>     int i;
>     int j;
>     for(i = 1;i <= n; i++){
>         lowcost[i] = 0;
>         visited[i] = 0;
>     }
>     for(i = 1; i <= n; i++){
>         for(j = 1; j <= n; j++)
>             g[i][j] = MAX;
>         g[i][i] = 0;
>     }
> 
> }
> 
> int getmin(int a, int b){
>     if(a > b)
>         a = b;
>     return a;
> }
> 
> int main()
> {
>     int n;
>     int m;
>     int i;
>     int j;
>     int k;
>     int x;
>     int y;
>     int dis;
>     int min;
>     int ans;
>     while(1){
>         scanf("%d", &n);
>         if(!n)
>             break;
>         scanf("%d", &m);
>         if(!m){
>             printf("0\n");
>             continue;
>         }
>         ans = 0;
>         init(n);
>         while(m--){
>             scanf("%d%d%d", &x, &y, &dis);
>             if(!g[x][y])
>                 g[x][y] = g[y][x] = dis;
>             else
>                 g[y][x] = g[x][y] = getmin(dis, g[x][y]);
>         }
>         for(i = 2; i <= n; i++)
>             lowcost[i] = g[1][i];
>         visited[1] = 1;
>         for(j = 2; j <= n; j++){
>             min = MAX;
>             for(i = 1; i <= n; i++){
>                 if(!visited[i] && lowcost[i] < min){
>                     min = lowcost[i];
>                     k = i;
>                 }
>             }
>             ans += min;
>             visited[k] = 1;
>             for(i = 1; i <= n; i++){
>                 if(!visited[i] && lowcost[i] > g[k][i])
>                     lowcost[i] = g[k][i];
>             }
>         }
>         printf("%d\n", ans);
>     }
>     return 0;
> }