#include <stdio.h>
#include <memory.h>
#include <vector>
#include <algorithm>

using namespace std;

struct edge {
	int from, to, cost;

	edge(int from, int to, int cost) :
		from(from), to(to), cost(cost) {}

	bool operator<(edge const &e) const {
		return cost < e.cost;
	}
};

int n, m, to, ta, ds[40001];
vector<edge> edges;

int find(int x) {
	return ds[x] == x ? x : ds[x] = find(ds[x]);
}

int main() {
	while(scanf("%d %d", &n, &m) && n != 0 && m != 0) {
		to = ta = 0;
		for(int i = 0; i < n; ++i)
			ds[i] = i;
		edges.clear();

		for(int i = 0, a, b, c; i < m; ++i) {
			scanf("%d %d %d", &a, &b, &c);
			edges.push_back(edge(a, b, c));
		}
		sort(edges.begin(), edges.end());

		for(int i = 0, a, b; i < m && ta < n - 1; ++i) {
			a = find(edges[i].from);
			b = find(edges[i].to);

			if(a != b) {
				ds[a] = b;
				to += edges[i].cost;
			}
		}

		printf("%d\n", to);
	}

	return 0;
}