/* ***********************************************

 Author        :Sun Yuefeng

 Created Time  :2016/11/9 18:26:37

 File Name     :tree.cpp

 ************************************************ */

 #include<cstdio>

 #include<iostream>

 #include<algorithm>

 #include<cmath>

 #include<cstring>

 #include<string>

 #include<bitset>

 #include<map>

 #include<set>

 #include<stack>

 #include<vector>

 #include<queue>

 #include<list>

 #define M(a,b) memset(a,b,sizeof(a))

 using namespace std;

 typedef long long ll;

 const int inf=0x3f3f3f3f;

 const int maxn=;

 const int maxm=;

 const int mod=1e7+;

 int dx[]= {,,,-,,-,,-};

 int dy[]= {,-,,,-,,,-};

 int f[maxn],tol,n,m;

 struct _edge

 {

     int u,v,w;

 }edge[maxm];

 bool cmp(_edge a,_edge b)

 {

     return a.w<b.w;

 }

 void addedge(int u,int v,int w)

 {

     edge[tol].u=u;

     edge[tol].v=v;

     edge[tol].w=w;

     tol++;

 }

 int _find(int x)

 {

     if(f[x]==-) return x;

     else return f[x]=_find(f[x]);

 }

 int kruskal()

 {

     M(f,-);

     sort(edge,edge+tol,cmp);

     int cnt=,ans=;

     int u,v,w,f1,f2;

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

     {

         u=edge[i].u;

         v=edge[i].v;

         w=edge[i].w;

         f1=_find(u);

         f2=_find(v);

         if(f1!=f2)

         {

             ans+=w;

             f[f1]=f2;

             cnt++;

         }

         if(cnt==n-) break;

     }

     return ans;

 }

 int main()

 {

     //freopen("in.txt","r",stdin);

     //freopen("out.txt","w",stdout);

     while(~scanf("%d%d",&n,&m)&&n)

     {

         tol=;

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

         {

             int u,v,w;

             scanf("%d%d%d",&u,&v,&w);

             addedge(u,v,w);

         }

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

     }

     return ;

 }