P10020 [AtCoder] AtCoder Beginner Contest 051 - Candidates of No Shortest Paths
普及+
题目描述

You are given an undirected connected weighted graph with N vertices and M edges that contains neither self-loops nor double edges.
The i-th (1≤i≤M) edge connects vertex a_i and vertex b_i with a distance of c_i.
Here, a self-loop is an edge where a_i = b_i (1≤i≤M), and double edges are two edges where (a_i,b_i)=(a_j,b_j) or (a_i,b_i)=(b_j,a_j) (1≤i<j≤M).
A connected graph is a graph where there is a path between every pair of different vertices.
Find the number of the edges that are not contained in any shortest path between any pair of different vertices.

Constraints

  • 2≤N≤100
  • N-1≤M≤min(N(N-1)/2,1000)
  • 1≤a_i,b_i≤N
  • 1≤c_i≤1000
  • c_i is an integer.
  • The given graph contains neither self-loops nor double edges.
  • The given graph is connected.

Input

The input is given from Standard Input in the following format:

N M
a_1 b_1 c_1
a_2 b_2 c_2
:
a_M b_M c_M

Output

Print the number of the edges in the graph that are not contained in any shortest path between any pair of different vertices.

Examples

Input

3 3
1 2 1
1 3 1
2 3 3

Output

1

Input

3 2
1 2 1
2 3 1

Output

0

输入格式

见题面

输出格式

见题面

样例输入
3 3 1 2 1 1 3 1 2 3 3
样例输出
1