#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<vector>
#include<queue>
#include<stack>
#include<cmath>
#include<set>
using namespace std;
#define rep(i,a,n) for (int i=a;i<n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
#define pb push_back
#define fi first
#define se second
typedef vector<int> VI;
typedef long long ll;
typedef pair<int,int> PII;
const int inf=1e9;
const ll mod=1000000007;
const double eps=1e-8;  //

const int maxn=210;//点数的最大值
const int maxm=20500;//边数的最大值
struct Node
{int from,to,next;double cap;
}edge[maxm];struct nod
{int u,v,w;nod(int a=0,int b=0,int c=0):u(a),v(b),w(c) {}
}e[550];int tol;
int dep[maxn];//dep为点的层次
int head[maxn];
int n,m;
void init()
{tol=0;memset(head,-1,sizeof(head));
}
void addedge(int u,int v,double w)//第一条边下标必须为偶数
{edge[tol].from=u;edge[tol].to=v;edge[tol].cap=w;edge[tol].next=head[u];head[u]=tol++;edge[tol].from=v;edge[tol].to=u;edge[tol].cap=0;edge[tol].next=head[v];head[v]=tol++;
}
int BFS(int start,int end)
{int que[maxn];int front,rear;front=rear=0;memset(dep,-1,sizeof(dep));que[rear++]=start;dep[start]=0;while(front!=rear){int u=que[front++];if(front==maxn)front=0;for(int i=head[u];i!=-1;i=edge[i].next){int v=edge[i].to;if(edge[i].cap>0&&dep[v]==-1){dep[v]=dep[u]+1;que[rear++]=v;if(rear>=maxn)rear=0;if(v==end)return 1;}}}return 0;
}
double dinic(int start,int end)
{double res=0;int top;int stack[maxn];//stack为栈，存储当前增广路int cur[maxn];//存储当前点的后继while(BFS(start,end)){memcpy(cur,head,sizeof(head));int u=start;top=0;while(1){if(u==end){double min=inf;int loc;for(int i=0;i<top;i++)if(min>edge[stack[i]].cap){min=edge[stack[i]].cap;loc=i;}for(int i=0;i<top;i++){edge[stack[i]].cap-=min;edge[stack[i]^1].cap+=min;}res+=min;top=loc;u=edge[stack[top]].from;}for(int i=cur[u];i!=-1;cur[u]=i=edge[i].next)if(edge[i].cap!=0&&dep[u]+1==dep[edge[i].to])break;if(cur[u]!=-1){stack[top++]=cur[u];u=edge[cur[u]].to;}else{if(top==0)break;dep[u]=-1;u=edge[stack[--top]].from;}}}return res;
}double check(double x)
{double ans=0;tol=0;rep(i,1,n+1) head[i]=-1;rep(i,1,m+1){if(e[i].w-x<0){ans+=e[i].w-x;continue;}addedge(e[i].u,e[i].v,e[i].w-x);addedge(e[i].v,e[i].u,e[i].w-x);}int st=1,ed=n;ans+=dinic(st,ed);return ans;
}int vis[maxn];
queue<int> q;
void bfs()
{while(!q.empty()) q.pop();vis[1]=1;q.push(1);while(!q.empty()){int u=q.front();q.pop();for(int i=head[u];i!=-1;i=edge[i].next){int v=edge[i].to;if(fabs(edge[i].cap)<eps) continue;if(vis[v]) continue;vis[v]=1;q.push(v);}}
}
set<int> sel;
int main()
{while(~scanf("%d%d",&n,&m)){rep(i,1,n+1) vis[i]=0;sel.clear();ll sum=0;int mi=inf;rep(i,1,m+1){scanf("%d%d%d",&e[i].u,&e[i].v,&e[i].w);sum+=1ll*e[i].w;mi=min(mi,e[i].w);}double l=1.0*mi/n,r=1.0*sum;double ans=0;while(1){double m=(l+r)/2;double res=check(m);if(fabs(res)<eps){ans=m;bfs();break;}if(res>0) l=m;else r=m;}rep(i,1,m+1){if(vis[e[i].u]+vis[e[i].v]==1)sel.insert(i);if(e[i].w<l)sel.insert(i);}printf("%d\n",(int)sel.size());set<int>::iterator it;int cnt=0;for(it=sel.begin();it!=sel.end();it++){cnt++;printf("%d%c",*it,cnt==sel.size()? '\n':' ');}}return 0;
}