#include <cstdio>
#include <vector>
#include <algorithm>
#include <cstring>

#define NMAX 1007
#define INF 10000000

using namespace std;

int n, m;
int q[NMAX];
vector <int> v[NMAX];
vector <int> Sol;
int dad[NMAX], Cap[NMAX][NMAX], Flux[NMAX][NMAX];
int a[NMAX], b[NMAX], c[NMAX], Viz[NMAX];

inline int dfs(int Nod){
    if(Nod == n)
        return 1;
    Viz[Nod] = 1;
    for(int i = 0; i < v[Nod].size(); ++ i){
        int it = v[Nod][i];
        if(Viz[it] == 0 && Flux[Nod][it] != Cap[Nod][it]){
            dad[it] = Nod;
            int ok = dfs(it);
            if(ok == 1)
                return 1;
        }
    }
    return 0;
}

inline int father(int Nod, int Min){
    if(Nod == 1)
        return Min;
    int Dad = dad[Nod];
    Min = min(Min, Cap[Dad][Nod] - Flux[Dad][Nod]);
    return father(dad[Nod], Min);
}

void father2(int Nod, int Min){
    if(Nod == 1)
        return;
    int Dad = dad[Nod];
    Flux[Nod][Dad] -= Min;
    Flux[Dad][Nod] += Min;
    father2(dad[Nod], Min);
}

void fluxmax(){
    int Maxflow = 0;
    memset(dad, -1, sizeof(dad));
    memset(Viz, 0, sizeof(Viz));
    while(dfs(1)){
        int Min = INF;
        Min = father(n, Min);
        father2(n, Min);
        memset(dad, -1, sizeof(dad));
        memset(Viz, 0, sizeof(Viz));
    }
}

int main(){
    freopen("critice.in", "r", stdin);
    freopen("critice.out", "w", stdout);
    scanf("%d %d\n", &n, &m);
    for(int i = 1; i <= m; ++i){
        scanf("%d %d %d\n", &a[i], &b[i], &c[i]);
        v[a[i]].push_back(b[i]);
        v[b[i]].push_back(a[i]);
        Cap[a[i]][b[i]] = c[i];
        Cap[b[i]][a[i]] = c[i];
        Flux[a[i]][b[i]] = 0;
        Flux[b[i]][a[i]] = 0;
    }
    fluxmax();
    printf("%d\n", Sol.size());
    for(int i = 0; i < Sol.size(); ++i)
        printf("%d\n", Sol[i]);
    return 0;
}