#include <bits/stdc++.h>
using namespace std;
int V, m;
int cost[200][200];
int mincost[200];
bool used[200];

int prim(){
  for(int i=0; i < V; ++i){
    mincost[i] = INT_MAX/2;
    used[i] = false;
  }
  mincost[0] = 0;
  int res = 0;

  while(true){
    int v = -1;
    for(int u=0; u < V; u++){
      if(!used[u] && (v == -1 || mincost[u] < mincost[v])) v = u;
    }

    if(v == -1) break;
    used[v] = true;
    res += mincost[v];

    for(int u=0; u < V; u++){
      mincost[u] = min(mincost[u], cost[v][u]);
    }
  }
  return res;
}

int main(void){
  while(cin >> V >> m, V | m){
    for(int i=0; i < V; i++)
      for(int j=0; j < m; j++)
        cost[i][j] = INT_MAX/2;
    for(int i=0; i < m; i++){
      int a, b, c; cin >> a >> b >> c;
      cost[a][b] = c;
      cost[b][a] = c;
    }
    cout << prim() << endl;
  }
  return 0;
}