Petya loves lucky numbers. We all know that lucky numbers are the positive integers whose decimal representations contain only the lucky digits 4 and 7. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not.

One day Petya encountered a tree with n vertexes. Besides, the tree was weighted, i. e. each edge of the tree has weight (a positive integer). An edge is lucky if its weight is a lucky number. Note that a tree with n vertexes is an undirected connected graph that has exactly n - 1 edges.

Petya wondered how many vertex triples (i, j, k) exists that on the way from i to j, as well as on the way from i to k there must be at least one lucky edge (all three vertexes are pairwise distinct). The order of numbers in the triple matters, that is, the triple (1, 2, 3) is not equal to the triple (2, 1, 3) and is not equal to the triple (1, 3, 2). 

Find how many such triples of vertexes exist.

Input

The first line contains the single integer n (1 ≤ n ≤ 105) — the number of tree vertexes. Next n - 1 lines contain three integers each: ui vi wi (1 ≤ ui, vi ≤ n, 1 ≤ wi ≤ 109) — the pair of vertexes connected by the edge and the edge's weight.

Output

On the single line print the single number — the answer.

Please do not use the %lld specificator to read or write 64-bit numbers in С++. It is recommended to use the cin, cout streams or the %I64d specificator.

Examples

Input

4
1 2 4
3 1 2
1 4 7


Output

16


Input

4
1 2 4
1 3 47
1 4 7447


Output

24

Note

The 16 triples of vertexes from the first sample are: (1, 2, 4), (1, 4, 2), (2, 1, 3), (2, 1, 4), (2, 3, 1), (2, 3, 4), (2, 4, 1), (2, 4, 3), (3, 2, 4), (3, 4, 2), (4, 1, 2), (4, 1, 3), (4, 2, 1), (4, 2, 3), (4, 3, 1), (4, 3, 2).

In the second sample all the triples should be counted: 4·3·2 = 24.
import java.io.*;
import java.util.*;
import java.math.*;
import java.text.DecimalFormat;
import java.text.NumberFormat;
 
public class Main {
      
    int mod = 1000000007;

    public class SegmentTree{

       int n;
       int[] tree;

       SegmentTree(int[] arr){

          this.n = arr.length; 
          this.tree = new int[2 * n];

          for(int i = n; i < 2 * n; i++){
              this.tree[i] = arr[i - n];
          }

          for(int i = n - 1; i >= 1; i--){
              this.tree[i] = Math.min(this.tree[2 * i], this.tree[2 * i + 1]);
          }

       }

       public int query(int l, int r){

          int res = Integer.MAX_VALUE;
          l = l + n;
          r = r + n;

          while(l < r){

              if(l % 2 == 1){
                  res = Math.min(res, tree[l]); 
                  l++;
              }

              if(r % 2 == 1){
                  r--;
                  res = Math.min(res, tree[r]);
              }

              l /= 2;
              r /= 2;
          }

          return res;
       }
    }

    
    HashMap<Integer, List<Integer>> map = new HashMap<>();
    int n;
    int[] visited;
    public void solve() throws IOException{
         
         n = in.nextInt();
         visited = new int[n + 1];
         for(int i = 1; i <= n; i++){
            map.put(i, new ArrayList<>());
         }

         for(int i = 0; i < n - 1; i++){
               
            int u = in.nextInt();
            int v = in.nextInt();
            int w = in.nextInt();
         
            if(isLucky(w))
               continue;
           
            map.get(u).add(v);
            map.get(v).add(u);
         }
        
         long cnt = 0;
         List<Long> res = new ArrayList<>();
         for(int i = 1; i <= n; i++){
            if(visited[i] == 0){
               long s = dfs(i);
               cnt += s;
               res.add(s);
            }
         }
         
         long a = 0;
         for(int i = 0; i < res.size(); i++){
            a += (res.get(i) * (cnt - res.get(i) - 1) * (cnt - res.get(i)));
         }
         out.println(a);
    }

    public long dfs(int u){

       visited[u] = 1;
       long res = 1;
       for(int v: map.get(u)){
          if(visited[v] == 0)
            res += dfs(v); 
       }
      
       return res;
    }


    public boolean isLucky(int n){
       while(n != 0){
         if(n % 10 != 4 && n % 10 != 7){
            return false;
         }
         n /= 10;
       }
       return true;
    }

    FastScanner in;
    PrintWriter out;
    
    static class FastScanner {
 
        BufferedReader br;
        StringTokenizer st;
 
        FastScanner(InputStream in) {
            br = new BufferedReader(new InputStreamReader(in));
            st = null;
        }
 
        String next() throws IOException {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }
 
        String nextLine() throws IOException {
            if (st == null || !st.hasMoreTokens())
                return br.readLine();
            StringBuilder result = new StringBuilder(st.nextToken());
            while (st.hasMoreTokens()) {
                result.append(" ");
                result.append(st.nextToken());
            }
            return result.toString();
        }
 
        int nextInt() throws IOException {
            return Integer.parseInt(next());
        }
 
        long nextLong() throws IOException {
            return Long.parseLong(next());
        }
 
        double nextDouble() throws IOException {
            return Double.parseDouble(next());
        }
 
    }
 
    void run() throws IOException {
        in = new FastScanner(System.in);
        out = new PrintWriter(System.out, false);
        solve();
        out.close();
    }
 
    public static void main(String[] args) throws IOException{
        new Main().run();
    }
 
    public void printArr(int[] arr){
        for(int i = 0; i < arr.length; i++){
            out.print(arr[i] + " ");
        }
        out.println();
    }
 
    public long gcd(long a, long b){
        if(a == 0) return b;
        return gcd(b % a, a);
    }

    public boolean isPrime(long num){

        if(num == 0 || num == 1){
            return false;
        }

        for(int i = 2; i * i <= num; i++){
            if(num % i == 0){
                return false;
            }
        }

        return true;
    }

    public class Pair<A, B>{
        public A x; 
        public B y;

        Pair(A x, B y){
            this.x = x;
            this.y = y;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            Pair<?, ?> pair = (Pair<?, ?>) o;
            if (!x.equals(pair.x)) return false;
            return y.equals(pair.y);
        }

        @Override
        public int hashCode() {
            int result = x.hashCode();
            result = 31 * result + y.hashCode();
            return result;
        }

    }

    class Tuple{
        int x; int y; int z;
        Tuple(int ix, int iy, int iz){
            x = ix;
            y = iy;
            z = iz;
        }
    }
}
