#include<cstdio>
#include<queue>
#include<cstring>
using namespace std;
struct muchie
{
    int x,y;
}muc[1001];
vector<int>v[1001];
int f[1001][1001],c[1001][1001],tata[1001];
int n,m,x,y,z,viz[1001],viz1[1001],sol[1001],k,i;
int BFS()
{
    queue<int>q;
    q.push(1);
    memset(viz,0,sizeof(viz));
    viz[1]=1;
    while(!q.empty())
    {
        int nod=q.front();
        q.pop();
        for (i=0;i<v[nod].size();++i)
        {
            int varf=v[nod][i];
            if (c[nod][varf]>f[nod][varf] && viz[varf]==0)
            {
                q.push(varf);
                tata[varf]=nod;
                viz[varf]=1;
            }
        }
    }
    return viz[n];
}
void BFS1()
{
    queue<int>q;
    q.push(n);
    viz1[n]=1;
    while(!q.empty())
    {
        int nod=q.front();
        q.pop();
        for (i=0;i<v[nod].size();++i)
        {
            int varf=v[nod][i];
            if (c[nod][varf]>f[nod][varf]*(-1) && viz1[varf]==0)
            {
                q.push(varf);
                tata[varf]=nod;
                viz1[varf]=1;
            }
        }
    }
}
int main()
{
    freopen("critice.in","r",stdin);
    freopen("critice.out","w",stdout);
    scanf("%d%d",&n,&m);
    for (i=1;i<=m;++i)
    {
        scanf("%d%d%d",&x,&y,&z);
        muc[i].x=x;
        muc[i].y=y;
        v[x].push_back(y);
        v[y].push_back(x);
        c[x][y]=z;
        c[y][x]=z;
    }
    int flux=0;
    while(BFS())
    {
        for (i=0;i<v[n].size();++i)
        {
            int nod=v[n][i];
            if (f[nod][n]==c[nod][n] || !viz[nod]) continue;
            tata[n]=nod;
            int fmin=c[tata[nod]][nod]-f[tata[nod]][nod];
            for (nod=n;nod!=1;nod=tata[nod])
                fmin=min(fmin,c[tata[nod]][nod]-f[tata[nod]][nod]);
            if (fmin==0) continue;
            for (nod=n;nod!=1;nod=tata[nod])
                {
                    f[tata[nod]][nod]+=fmin;
                    f[nod][tata[nod]]-=fmin;
                }
            flux+=fmin;
        }
    }
    x=BFS();
    BFS1();
    for (i=1;i<=m;++i)
        if ((viz[muc[i].x]==1 && viz1[muc[i].y]==1) || (viz[muc[i].y]==1 && viz1[muc[i].x]==1))
            sol[++k]=i;
    printf("%d\n",k);
    for (i=1;i<=k;++i) printf("%d\n",sol[i]);
    return 0;
}