#include <stdio.h>
#include <string.h>
#define INF 1000000000
#define MAXN 1000
#define MAXM 10000
int u[MAXN+1], a[MAXM], b[MAXM], ans[MAXN+1];
int n, from[MAXN+1], q[MAXN+1], v[MAXN+1][MAXN+1], f[MAXN+1][MAXN+1], c[MAXN+1][MAXN+1], viz[MAXN+1];
inline int bfs(){
    int st, dr, p, x;
    st=0;
    dr=1;
    q[0]=1;
    memset(from, 0, sizeof from);
    memset(viz, 0, sizeof viz);
    viz[1]=1;
    while((st<dr)&&(viz[n]==0)){
        for(p=1; p<=v[q[st]][0]; p++){
            x=v[q[st]][p];
            if((viz[x]==0)&&(c[q[st]][x]>f[q[st]][x])){
                from[x]=q[st];
                viz[x]=1;
                q[dr++]=x;
            }
        }
        st++;
    }
    return viz[n];
}
void dfs1(int x){
    int p, y;
    u[x]=1;
    for(p=1; p<=v[x][0]; p++){
        y=v[x][p];
        if((u[y]!=1)&&(c[x][y]!=f[x][y])&&(c[x][y]!=f[y][x])){
            dfs1(y);
        }
    }
}
void dfs2(int x){
    int p, y;
    u[x]=2;
    for(p=1; p<=v[x][0]; p++){
        y=v[x][p];
        if((u[y]!=2)&&(c[x][y]!=f[x][y])&&(c[x][y]!=f[y][x])){
            dfs2(y);
        }
    }
}
int main(){
    int m, i, z, min, p, x;
    FILE *fin, *fout;
    fin=fopen("critice.in", "r");
    fout=fopen("critice.out", "w");
    fscanf(fin, "%d%d", &n, &m);
    for(i=0; i<m; i++){
        fscanf(fin, "%d%d%d", &a[i], &b[i], &z);
        v[a[i]][++v[a[i]][0]]=b[i];
        v[b[i]][++v[b[i]][0]]=a[i];
        c[a[i]][b[i]]+=z;
        c[b[i]][a[i]]+=z;
    }
    while(bfs()){
        for(p=1; p<=v[n][0]; p++){
            x=v[n][p];
            if((viz[x])&&(c[x][n]>f[x][n])){
                from[n]=x;
                min=INF;
                i=n;
                while(i!=1){
                    if(min>c[from[i]][i]-f[from[i]][i]){
                        min=c[from[i]][i]-f[from[i]][i];
                    }
                    i=from[i];
                }
                i=n;
                while(i!=1){
                    f[from[i]][i]+=min;
                    f[i][from[i]]-=min;
                    i=from[i];
                }
            }
        }
    }
    dfs1(1);
    dfs2(n);
    ans[0]=0;
    for(i=0; i<m; i++){
        if(((u[a[i]]==1)&&(u[b[i]]==2))||((u[a[i]]==2)&&(u[b[i]]==1))){
            ans[++ans[0]]=i+1;
        }
    }
    for(i=0; i<=ans[0]; i++){
        fprintf(fout, "%d\n", ans[i]);
    }
    fclose(fin);
    fclose(fout);
    return 0;
}