1 #include "map"
 2 #include "queue"
 3 #include "math.h"
 4 #include "stdio.h"
 5 #include "string.h"
 6 #include "iostream"
 7 #include "algorithm"
 8 #define abs(x) x > 0 ? x : -x
 9 #define max(a,b) a > b ? a : b
10 #define min(a,b) a < b ? a : b
11 
12 using namespace std;
13 
14 int arc[55][55];
15 
16 void Prime(int n){
17     int i,j,k,m;
18     int sumweight = 0;
19     int addnew[55];
20     int lowcost[55];
21     for(i=1; i<=n; i++){
22         addnew[i] = 0;
23         lowcost[i] = arc[1][i];
24     }
25     addnew[1] = 1;
26     for(i=1; i<n; i++){
27         k = 0,m = 999999;
28         for(j=2; j<=n; j++){
29             if(!addnew[j] && lowcost[j]<m){
30                 m = lowcost[j];
31                 k = j;
32             }
33         }
34         sumweight += lowcost[k];
35         addnew[k] = 1;
36         for(j=2; j<=n; j++){
37             if(!addnew[j] && arc[k][j]<lowcost[j])
38                 lowcost[j] = arc[k][j];
39         }
40     }
41     printf("%d\n",sumweight);
42 }
43 
44 int main(){
45     int n,m,i,a,b,c;
46     while(scanf("%d",&n)&&n){
47         memset(arc,111,sizeof(arc));
48         scanf("%d",&m);
49         while(m--){
50             scanf("%d%d%d",&a,&b,&c);
51             if(arc[a][b]>c){
52                 arc[a][b] = c;
53                 arc[b][a] = c;
54             }
55         }
56         Prime(n);
57     }
58     return 0;
59 }