#include <iostream>
#include <fstream>

using namespace std;

#define NMAX 100002

ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n, m;
int conex[NMAX];
int maxim = 0;

void Read(void)
{
	fin >> n >> m;
	int a, b;
	for (int i = 0; i < m; i++)
	{
		conex[i + 1]++;
		fin >> a >> b;
		conex[a]++; conex[b]++;
		int c = conex[a];
		conex[a] += conex[b] - 1;
		conex[b] += c - 1;
		if (maxim < conex[a])
		{
			maxim = conex[a];
		}
		if (maxim < conex[b])
		{
			maxim = conex[b];
		}
	}
}

int main(void)
{
	Read();
	fout << maxim;
	return 0;
}