#include <stdio.h>

#define NMAX 1000
#define MMAX 10000

#define INF 0x3f3f3f3f

short n, m, k;
short ans[MMAX];
short u[NMAX], v[NMAX];
short capacity[NMAX][NMAX];
short g[NMAX][NMAX];
short queue[NMAX];
short parent[NMAX];

inline const int& min(const int& a, const int& b)
{
    return a <= b ? a : b;
}

int main()
{
    freopen("critice.in", "r", stdin);
    freopen("critice.out", "w", stdout);

    scanf("%hd %hd", &n, &m);
    for(int i = 0; i < m; i++)
    {
        int w;
        scanf("%hd %hd %d", &u[i], &v[i], &w);
        u[i]--; v[i]--;
        capacity[u[i]][v[i]] = w;
        capacity[v[i]][u[i]] = w;
        g[u[i]][++g[u[i]][0]] = v[i];
        g[v[i]][++g[v[i]][0]] = u[i];
    }

    int flow = 0;
    while(true)
    {
        for(int i = 1; i < n; i++)
            parent[i] = -1;

        queue[0] = 1;
        queue[1] = 0;
        for(int i = 1; i <= queue[0]; i++)
        {
            int u = queue[i];
            for(int i = 1; i <= g[u][0]; i++)
            {
                int v = g[u][i];
                if(parent[v] == -1 && capacity[u][v])
                {
                    parent[v] = u;
                    queue[++queue[0]] = v;
                }
            }
        }

        if(parent[n - 1] == -1)
            break;
        
        for(int i = 1; i <= g[n - 1][0]; i++)
        {
            int node = g[n - 1][i];
            if(parent[node] != -1 && capacity[node][n - 1])
            {
                parent[n - 1] = node;

                int maxflow = INF;
                for(node = n - 1; node != 0; node = parent[node])
                    maxflow = min(maxflow, capacity[parent[node]][node]);
                
                if(maxflow == 0)
                    continue;
                
                for(node = n - 1; node != 0; node = parent[node])
                {
                    capacity[parent[node]][node] -= maxflow;
                    capacity[node][parent[node]] -= maxflow;
                }

                flow += maxflow;
            }
        }
    }

    for(int i = 0; i < m; i++)
    {
        capacity[u[i]][v[i]]++;
        capacity[v[i]][u[i]]++;

        for(int i = 1; i < n; i++)
            parent[i] = -1;
        
        queue[0] = 1;
        queue[1] = 0;
        
        for(int i = 1; i <= queue[0]; i++)
        {
            int u = queue[i];
            for(int i = 1; i <= g[u][0]; i++)
            {
                int v = g[u][i];
                if(parent[v] == -1 && capacity[u][v])
                {
                    parent[v] = u;
                    queue[++queue[0]] = v;
                }
            }
        }

        if(parent[n - 1] != -1)
            ans[k++] = i + 1;
        
        capacity[u[i]][v[i]]--;
        capacity[v[i]][u[i]]--;
    }

    printf("%d\n", k);
    for(int i = 0; i < k; i++)
        printf("%d\n", ans[i]);
    return 0;
}