#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < (n); i++)
#define REP(i, init, n) for (int i = init; i < (n); i++)

using namespace std;
using ll = long long int;
using P = pair<int, int>;
using T = tuple<int, int, int>;
using edge = struct
{
    int to, cost;
};

const int MOD = 1e9 + 7;
const int iINF = 1e9;
const long long int llINF = 1e18;
const double PI = acos(-1.0);

const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};

class UnionFind
{
  private:
    vector<int> par;
    vector<int> sizes;

  public:
    UnionFind(int N) : par(N), sizes(N, 1)
    {
        rep(i, N) par[i] = i;
    }

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

        return par[x] = find(par[x]);
    }

    void unite(int x, int y)
    {
        x = find(x);
        y = find(y);

        if (x == y)
            return;

        if (sizes[x] < sizes[y])
            swap(x, y);

        par[y] = x;
        sizes[x] += sizes[y];
    }

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

    int size(int x)
    {
        return sizes[find(x)];
    }
};

int main()
{
    int N, M;
    while (cin >> N >> M, N)
    {
        vector<T> edges;

        rep(i, M)
        {
            int a, b, cost;
            cin >> a >> b >> cost;

            edges.push_back(make_tuple(cost, a, b));
        }

        sort(edges.begin(), edges.end());

        UnionFind uf(N);

        int ans = 0;

        for(auto e : edges)
        {
            int to, from, cost;
            tie(cost, to, from) = e;

            if(uf.same(from, to)) continue;

            uf.unite(from, to);

            ans += cost;

        }

        cout << ans << endl;
    }
    return 0;
}
