#include <stdio.h>
#include <fstream>
#include <string>
using namespace std;

int main()
{
	bool graph[101][101];
	int nodes,cases,x,y,a,b,c,d,bridge,check;
	ifstream infile;
	ofstream outfile;
	infile.open("DATA5.txt", ios::in);
	outfile.open("OUT5.txt", ios::out);
	infile >> nodes;
	infile >> cases;
	bridge=0;
	for (c=1; c<=5; c++)
	{
	for (a=1; a<=101; a++)
	{
		for (b=1; b<=101; b++)
		{
			graph[a][b]=false;
		}
	}
	for (a=1; a<=cases; a++)
	{
		infile >> x >> y;
		graph[x][y]=true;
		graph[y][x]=true;
	}	
	for (a=1; a<=nodes; a++)
	{	
		check=0;
		for(b=1; b<=nodes; b++)
		{
			
			if (graph[a][b])
			{
				check++;
			//	printf("1");
			}
		//	else
			//	printf("0");
		}	
	//	printf("\n");
		if (check==1)
			bridge++;
	}
	outfile << bridge <<"\n";
	}
	return 0;
}