The city Valera lives in is going to hold elections to the city Parliament.

The city has n districts and n - 1 bidirectional roads. We know that from any district there is a path along the roads to any other district. Let's enumerate all districts in some way by integers from 1 to n, inclusive. Furthermore, for each road the residents decided if it is the problem road or not. A problem road is a road that needs to be repaired.

There are n candidates running the elections. Let's enumerate all candidates in some way by integers from 1 to n, inclusive. If the candidate number i will be elected in the city Parliament, he will perform exactly one promise — to repair all problem roads on the way from the i-th district to the district 1, where the city Parliament is located.

Help Valera and determine the subset of candidates such that if all candidates from the subset will be elected to the city Parliament, all problem roads in the city will be repaired. If there are several such subsets, you should choose the subset consisting of the minimum number of candidates.

Input

The first line contains a single integer n (2 ≤ n ≤ 105) — the number of districts in the city.

Then n - 1 lines follow. Each line contains the description of a city road as three positive integers xi, yi, ti (1 ≤ xi, yi ≤ n, 1 ≤ ti ≤ 2) — the districts connected by the i-th bidirectional road and the road type. If ti equals to one, then the i-th road isn't the problem road; if ti equals to two, then the i-th road is the problem road.

It's guaranteed that the graph structure of the city is a tree.

Output

In the first line print a single non-negative number k — the minimum size of the required subset of candidates. Then on the second line print k space-separated integers a1, a2, ... ak — the numbers of the candidates that form the required subset. If there are multiple solutions, you are allowed to print any of them.

Examples

Input

5
1 2 2
2 3 2
3 4 2
4 5 2


Output

1
5 


Input

5
1 2 1
2 3 2
2 4 1
4 5 1


Output

1
3 


Input

5
1 2 2
1 3 2
1 4 2
1 5 2


Output

4
5 4 3 2 
import java.io.*;
import java.util.*;
import java.lang.*;
import java.util.HashMap;
public class templ implements Runnable {
    class pair
    {
        int node,type;
        pair(int f,int s)
        {
            node=f;
            type=s;
        }
    }
    public static ArrayList<pair> g[]=new ArrayList[1000000];
    public static int vis[]=new int[1000000];
    public static int vis1[]=new int[1000000];
    public static int vis2[]=new int[1000000];
    public static int val[]=new int[1000000];
    public static int v[]=new int[1000000];
    public static int an[]=new int[1000000];
    public static int d[]=new int[1000000];
    public static int o=0;
    void dfs(int n,int p)
    {
        vis[n]=1;
        for(int i=0;i<g[n].size();i++)
        {
            int u=g[n].get(i).node;
            if(vis[u]==0)
            {
                dfs(u, n);
            }
        }
    }
    void ddffss(int n)
    {
        vis1[n]=1;
        for(int i=0;i<g[n].size();i++)
        {
            int u=g[n].get(i).node;
            if(vis1[u]==0)
            {
                if(g[n].get(i).type==2)
                    val[u]=1;
                ddffss(u);
            }
        }
    }
    void dp(int n)
    {
        if(val[n]==1)
            d[n]=1;
        vis2[n]=1;
        for(int i=0;i<g[n].size();i++)
        {
            int u=g[n].get(i).node;
            if(vis2[u]==0)
            {
                dp(u);
                d[n]+=d[u];
            }
        }
    }
    int binarySearch(int arr[], int l, int r, int x)
    {
        if (r >= l)
        {
            int mid = l + (r - l)/2;
            if (arr[mid] == x)
                return mid;
            if (arr[mid] > x)
                return binarySearch(arr, l, mid-1, x);
            return binarySearch(arr, mid+1, r, x);
        }
        return -1;
    }
    void merge1(int arr[], int l, int m, int r)
    {
        int n1 = m - l + 1;
        int n2 = r - m;
        int L[] = new int [n1];
        int R[] = new int [n2];
        for (int i=0; i<n1; ++i)
            L[i] = arr[l + i];
        for (int j=0; j<n2; ++j)
            R[j] = arr[m + 1+ j];
        int i = 0, j = 0;
        int k = l;
        while (i < n1 && j < n2)
        {
            if (L[i]<=R[j])
            {
                arr[k] = L[i];
                i++;
            }
            else
            {
                arr[k] = R[j];
                j++;
            }
            k++;
        }
        while (i < n1)
        {
            arr[k] = L[i];
            i++;
            k++;
        }
        while (j < n2)
        {
            arr[k] = R[j];
            j++;
            k++;
        }
    }
    void sort1(int arr[], int l, int r)
    {
        if (l < r)
        {
            int m = (l+r)/2;
            sort1(arr, l, m);
            sort1(arr , m+1, r);
            merge1(arr, l, m, r);
        }
    }
    void merge3(int arr[],int arr1[],int arr2[], int l, int m, int r)
    {
        int n1 = m - l + 1;
        int n2 = r - m;
        int L[] = new int [n1];
        int R[] = new int [n2];
        int L1[]=new int[n1];
        int R1[]=new int[n2];
        int L2[]=new int[n1];
        int R2[]=new int[n2];
        //long L3[]=new long[n1];
        //long R3[]=new long[n2];
        for (int i=0; i<n1; ++i)
        {
            L[i] = arr[l + i];
            L1[i]=arr1[l+i];
            L2[i]=arr2[l+i];
            //L3[i]=arr3[l+i];
        }
        for (int j=0; j<n2; ++j)
        {
            R[j] = arr[m + 1+ j];
            R1[j]=arr1[m+1+j];
            R2[j]=arr2[m+1+j];
            //R3[j]=arr3[m+1+j];
        }
        int i = 0, j = 0;
        int k = l;
        while (i < n1 && j < n2)
        {
            if (L[i] <= R[j])
            {
                arr[k] = L[i];
                arr1[k]=L1[i];
                arr2[k]=L2[i];
                //arr3[k]=L3[i];
                i++;
            }
            else
            {
                arr[k] = R[j];
                arr1[k]=R1[j];
                arr2[k]=R2[j];
                //arr3[k]=R3[j];
                j++;
            }
            k++;
        }
        while (i < n1)
        {
            arr[k] = L[i];
            arr1[k]=L1[i];
            arr2[k]=L2[i];
            //arr3[k]=L3[i];
            i++;
            k++;
        }
        while (j < n2)
        {
            arr[k] = R[j];
            arr1[k]=R1[j];
            arr2[k]=R2[j];
            //arr3[k]=R3[j];
            j++;
            k++;
        }
    }
    void sort3(int arr[],int arr1[],int arr2[], int l, int r)
    {
        if (l < r)
        {
            int m = (l+r)/2;
            sort3(arr,arr1,arr2, l, m);
            sort3(arr ,arr1,arr2, m+1, r);
            merge3(arr,arr1,arr2,l, m, r);
        }
    }
    void merge2(int arr[],int arr1[],int l, int m, int r)
    {
        int n1 = m - l + 1;
        int n2 = r - m;
        int L[] = new int [n1];
        int R[] = new int [n2];
        int L1[]=new int[n1];
        int R1[]=new int[n2];
        for (int i=0; i<n1; ++i)
        {
            L[i] = arr[l + i];
            L1[i]=arr1[l+i];
        }
        for (int j=0; j<n2; ++j)
        {
            R[j] = arr[m + 1+ j];
            R1[j]=arr1[m+1+j];
        }
        int i = 0, j = 0;
        int k = l;
        while (i < n1 && j < n2)
        {
            if (L[i] <= R[j])
            {
                arr[k] = L[i];
                arr1[k]=L1[i];
                i++;
            }
            else
            {
                arr[k] = R[j];
                arr1[k]=R1[j];
                j++;
            }
            k++;
        }
        while (i < n1)
        {
            arr[k] = L[i];
            arr1[k]=L1[i];
            i++;
            k++;
        }
        while (j < n2)
        {
            arr[k] = R[j];
            arr1[k]=R1[j];
            j++;
            k++;
        }
    }
    void sort2(int arr[],int arr1[],int l, int r)
    {
        if (l < r)
        {
            int m = (l+r)/2;
            sort2(arr,arr1, l, m);
            sort2(arr ,arr1, m+1, r);
            merge2(arr,arr1,l, m, r);
        }
    }
    void merge4(int arr[],int arr1[],int arr2[],int arr3[], int l, int m, int r)
    {
        int n1 = m - l + 1;
        int n2 = r - m;
        int L[] = new int [n1];
        int R[] = new int [n2];
        int L1[]=new int[n1];
        int R1[]=new int[n2];
        int L2[]=new int[n1];
        int R2[]=new int[n2];
        int L3[]=new int[n1];
        int R3[]=new int[n2];
        for (int i=0; i<n1; ++i)
        {
            L[i] = arr[l + i];
            L1[i]=arr1[l+i];
            L2[i]=arr2[l+i];
            L3[i]=arr3[l+i];
        }
        for (int j=0; j<n2; ++j)
        {
            R[j] = arr[m + 1+ j];
            R1[j]=arr1[m+1+j];
            R2[j]=arr2[m+1+j];
            R3[j]=arr3[m+1+j];
        }
        int i = 0, j = 0;
        int k = l;
        while (i < n1 && j < n2)
        {
            if (L[i] <= R[j])
            {
                arr[k] = L[i];
                arr1[k]=L1[i];
                arr2[k]=L2[i];
                arr3[k]=L3[i];
                i++;
            }
            else
            {
                arr[k] = R[j];
                arr1[k]=R1[j];
                arr2[k]=R2[j];
                arr3[k]=R3[j];
                j++;
            }
            k++;
        }
        while (i < n1)
        {
            arr[k] = L[i];
            arr1[k]=L1[i];
            arr2[k]=L2[i];
            arr3[k]=L3[i];
            i++;
            k++;
        }
        while (j < n2)
        {
            arr[k] = R[j];
            arr1[k]=R1[j];
            arr2[k]=R2[j];
            arr3[k]=R3[j];
            j++;
            k++;
        }
    }
    void sort4(int arr[],int arr1[],int arr2[],int arr3[], int l, int r)
    {
        if (l < r)
        {
            int m = (l+r)/2;
            sort4(arr,arr1,arr2,arr3, l, m);
            sort4(arr ,arr1,arr2,arr3, m+1, r);
            merge4(arr,arr1,arr2,arr3,l, m, r);
        }
    }
    public int justsmall(int a[],int l,int r,int x)
    {
        int p=-1;
        while(l<=r)
        {
            int mid=(l+r)/2;
            if(a[mid]<=x)
            {
                p=mid;
                l=mid+1;
            }
            else
                r=mid-1;
        }
        return p;
    }
    public int justlarge(int a[],int l,int r,int x)
    {
        int p=0;
        while(l<=r)
        {
            int mid=(l+r)/2;
            if(a[mid]<=x)
            {
                l=mid+1;
            }
            else
            {
                p=a[mid];
                r = mid - 1;
            }
        }
        return p;
    }
    long gcd(long x,long y)
    {
        if(x%y==0)
            return y;
        else
            return(gcd(y,x%y));
    }
    long fact(long n)
    {
        long ans=1;
        for(int i=1;i<=n;i++)
            ans*=i;
        return ans;
    }
    public static void main(String args[])throws Exception
    {
        new Thread(null,new templ(),"templ",1<<26).start();
    }
    public void run() {
        try
        {
            InputReader in = new InputReader(System.in);
            PrintWriter out = new PrintWriter(System.out);
            templ ob=new templ();
            int n=in.ni();
            for(int i=1;i<=n;i++)
            {
                g[i]=new ArrayList();
            }
            for(int i=1;i<n;i++)
            {
                int u=in.ni();
                int v=in.ni();
                int t=in.ni();
                pair p1=new pair(v,t);
                pair p2=new pair(u,t);
                g[u].add(p1);
                g[v].add(p2);
            }
            ddffss(1);
            dp(1);
            for(int i=2;i<=n;i++)
            {
                if(val[i]==1&&d[i]==1)
                {
                    an[o]=i;
                    o++;
                }
            }
            out.println(o);
            for(int i=0;i<o;i++)
                out.print(an[i]+" ");
            out.close();
        }
        catch(Exception e){
            return;
        }
    }
    static class InputReader {

        private final InputStream stream;
        private final byte[] buf = new byte[8192];
        private int curChar, snumChars;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (snumChars == -1)
                throw new InputMismatchException();
            if (curChar >= snumChars) {
                curChar = 0;
                try {
                    snumChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (snumChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public int ni() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public long nl() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            long res = 0;
            do {
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public int[] nextIntArray(int n) {
            int a[] = new int[n];
            for (int i = 0; i < n; i++) {
                a[i] = ni();
            }
            return a;
        }

        public String readString() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public String nextLine() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isEndOfLine(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        private boolean isEndOfLine(int c) {
            return c == '\n' || c == '\r' || c == -1;
        }

    }
}