#include <algorithm>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <limits>
#include <stack>
#include <string>
#include <vector>

#define FOR(i,k,n) for (int (i)=(k); (i)<(n); ++(i))
#define rep(i,n) FOR(i,0,n)
#define pb push_back
#define eb emplace_back
#define all(v) begin(v), end(v)

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef vector<vector<int> > vvi;
template<class T> using vv=vector<vector< T > >;

struct union_find {
    int n;
    vi d;
    union_find() {}
    union_find(int n_): n(n_), d(n, -1) {}
    int root(int v) {
        if (d[v] < 0) {
            return v;
        }
        return d[v] = root(d[v]);
    }
    int size(int v) {
        return -d[root(v)];
    }
    bool unite(int x, int y) {
        x = root(x);
        y = root(y);
        if (x == y) {
            return false;
        }
        if (size(x) < size(y)) {
            swap(x, y);
        }
        d[x] += d[y];
        d[y] = x;
        return true;
    }
};

int main() {
    while (true) {
        int n, m;
        cin >> n >> m;
        if ( n == 0 ) { break; }
        vvi edges(m);
        rep (i, m) {
            int a, b, cost;
            cin >> a >> b >> cost;
            edges[i] = {cost, a, b};
        }
        sort(all(edges));

        int ans = 0;
        union_find uf(n);
        rep (i, m) {
            if ( uf.unite(edges[i][1], edges[i][2]) ) {
                ans += edges[i][0];
            }
        }
        printf("%d\n", ans);
    }
    return 0;
}