#include <stdio.h>

//#define DEBUG

#ifdef DEBUG
#define INPUT_FILE "C:\\Users\\Maksim Ignatyev\\CLionProjects\\AaDS\\cats\\taskR\\input.txt"
#define OUTPUT_FILE "C:\\Users\\Maksim Ignatyev\\CLionProjects\\AaDS\\cats\\taskR\\output.txt"
#else
#define INPUT_FILE "input.txt"
#define OUTPUT_FILE "output.txt"
#endif

#define INF 11

int uv_to_i(int u, int v);

int graph[499500];
signed char weights[499500];

int min_edge[1000];
int out_edge[1000];
char visited[1000];

int main() {

    FILE *input = fopen(INPUT_FILE, "r");
    FILE *output = fopen(OUTPUT_FILE, "w+");

    int n, m;

    fscanf(input, "%d %d", &n, &m);

    for (int i = 0; i < 499500; i++) {
        graph[i] = -1;
    }

    for (int i = 0; i < 1000; i++) {
        min_edge[i] = INF;
        out_edge[i] = -1;
        visited[i] = 0;
    }

    for (int i = 0; i < m; i++) {
        int u, v;
        int w;
        fscanf(input, "%d %d %d", &u, &v, &w);
        graph[uv_to_i(u, v)] = i;
        weights[i] = (signed char) w;
    }

    fclose(input);

    min_edge[0] = 0;

    for (int i = 0; i < n; i++) {

        int v = -1;

        for (int j = 0; j < n; j++) {
            if (visited[j] == 0 && (v == -1 || min_edge[j] < min_edge[v])) {
                v = j;
            }
        }

        visited[v] = 1;

        if(out_edge[v] != -1){
            fprintf(output, "%d\n", graph[uv_to_i(v, out_edge[v])]);
        }

        for (int j = 0; j < n; j++) {
            if(graph[uv_to_i(i, j)] != -1 && weights[graph[uv_to_i(v, j)]] < min_edge[j]){
                min_edge[j] = weights[graph[uv_to_i(v, j)]];
                out_edge[j] = v;
            }
        }

    }

    fclose(output);

}

int uv_to_i(int u, int v) {
    if (v < u) {
        return (((u - 1) * u) / 2) + v;
    }
    return (((v - 1) * v) / 2) + u;
}