#include <iostream>
#include <algorithm>
using namespace std;

#define MAX_N 100

int par[MAX_N];
int rank[MAX_N];

#define MAX_E 100
struct edge { int u, v, cost; };
edge es[MAX_E];

int V, E;

void init_union_find(int n) {
  for(int i=0; i<n; i++) {
    par[i] = i;
    rank[i] = 0;
  }
}

int find(int x) {
  if(par[x] == x) {
    return x;
  } else {
    return par[x] = find(par[x]);
  }
}

void unite(int x, int y) {
  x = find(x);
  y = find(y);
  if(x == y) return;
  
  if(rank[x] < rank[y]) {
    par[x] = y;
  } else {
    par[y] = x;
    if(rank[x] == rank[y]) rank[x] ++;
  }
}

bool same(int x, int y) {
  return find(x) == find(y);
}

bool comp(const edge& e1, const edge& e2) {
  return e1.cost < e2.cost;
}

int kruskal() {
  sort(es, es + E, comp);
  init_union_find(V);
  int res = 0;
  for(int i=0; i<E; i++) {
    edge e = es[i];
    if(!same(e.u, e.v)) {
      unite(e.u, e.v);
      res += e.cost;
    }
  }
  return res;
}

int main() {

  while(cin >> V >> E && (V||E)) {
    for(int i=0; i<E; i++) {
      int a, b, c;
      cin >> a >> b >> c;
      es[i].u = a, es[i].v = b, es[i].cost = c;
    }
    cout << kruskal() << endl;
  }
  
  return 0;
}