public static void main(String[] args) throws IOException {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String line = null;
while ((line = reader.readLine()) != null) {
StringTokenizer token = new StringTokenizer(line);
int n = Integer.parseInt(token.nextToken());
int m = Integer.parseInt(token.nextToken());
if (n == 0 && m == 0) {
break;
}
for (int i = 0; i < n; i++) {
parentRank[i][0] = i;
parentRank[i][1] = 0;
}
edgeList.clear();
for (int i = 0; i < m; i++) {
token = new StringTokenizer(reader.readLine());
int x = Integer.parseInt(token.nextToken());
int y = Integer.parseInt(token.nextToken());
int w = Integer.parseInt(token.nextToken());
edgeList.add(new Edge(x, y, w));
}
List<Integer> maxWeights = new ArrayList<Integer>();
Collections.sort(edgeList);
int maxWeight = 0;
for (int i = 0; i < edgeList.size(); i++) {
Edge edge = edgeList.get(i);
int x = find(edge.a);
int y = find(edge.b);
if (x != y) {
maxWeight = Math.max(maxWeight, edge.weight);
union(x, y);
} else {
maxWeights.add(Math.max(maxWeight, edge.weight));
}
}
if (maxWeights.size() > 0) {
for (int i = 0; i < maxWeights.size(); i++) {
if (i + 1 != maxWeights.size()) {
System.out.print(maxWeights.get(i) + " ");
} else {
System.out.print(maxWeights.get(i));
}
}
System.out.println();
} else {
System.out.println("forest");
}
}
}
