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

// =======================
// ------ graph ------ //
using Weight = int;
using Flow = int;
struct Edge {
    int src, dst;
    Weight weight;
    Flow cap;
    Edge() : src(0), dst(0), weight(0) { }
    Edge(int s, int d, Weight w) : src(s), dst(d), weight(w) { }
};
bool operator < (const Edge &e, const Edge &f) {
    return e.weight != f.weight ? e.weight > f.weight : // pqが降順のため
        e.src != f.src ? e.src < f.src : e.dst < f.dst;
}
using Edges = vector<Edge>;
using Graph = vector<Edges>;

void add_edge1(Graph &g, int a, int b, Weight w = 1) {
    g[a].emplace_back(a, b, w);
}

// ------ disjoint set ------ //
struct UnionFind {
    vector<int> data;
    int __size;
    UnionFind(int size) : data(size, -1), __size(size) { }
    bool unionSet(int x, int y) {
        if ((x = root(x)) != (y = root(y))) {
            if (data[y] < data[x]) swap(x, y);  // par -> child とは限らない
            data[x] += data[y]; data[y] = x; __size--;
        }
        return x != y;
    }
    bool findSet(int x, int y) { return root(x) == root(y); }
    int root(int x) { return data[x] < 0 ? x : data[x] = root(data[x]); }
    int size(int x) { return -data[root(x)]; }
    int size() { return __size; }
    vector<int> subset_roots() {
        vector<int> roots;
        for (int i = 0; i < data.size(); i++) if (data[i] < 0) roots.push_back(i);
        return roots;
    }
};

// ------ minimumSpanningForest ------ //
pair<Weight, Edges> kruskal(priority_queue<Edge> &PQ, int n) {
    UnionFind uf(n);
    Weight total = 0;
    Edges F;
    while (F.size() < n-1 && !PQ.empty()) {
        Edge e = PQ.top(); PQ.pop();
        if (uf.unionSet(e.src, e.dst)) {
            F.push_back(e);
            total += e.weight;
        }
    }
    return pair<Weight, Edges>(total, F);
}
// =======================

int main() {
    int n, m;
    while (cin >> n >> m, n) {
        priority_queue<Edge> PQ;
        for (int i = 0; i < m; i++) {
            int a, b, cost; cin >> a >> b >> cost;
            PQ.push(Edge{a, b, cost});
        }
        pair<Weight, Edges> res = kruskal(PQ, n);
        cout << res.first << endl;
    }
    return 0;
}
