#include <bits/stdc++.h>
using namespace std;

#define FOR(i, a, b) for (int i=(a); i<(b); i++)
#define FORD(i, a, b) for (int i=(a); i>(b); i--)
#define ALL(w) w.begin(), w.end()
#define SZ(x) ((int)(x).size())
#define pb push_back

const int maxL = 19, maxN = 1 << maxL;

int jp[maxL][maxN];
vector <int> G[maxN];
int D[maxN], parent[maxN];
set <int> S[maxN];

int lca(int a, int b) // D[a] == D[b]
{
	if (a == b)
		return a;
	FORD(l, maxL-1, -1)
		if (jp[l][a] != jp[l][b])
			a = jp[l][a], b = jp[l][b];
	return jp[0][a];
}

void disc(int v, int fat)
{
	jp[0][v] = fat;
	FOR(l, 1, maxL)
		jp[l][v] = jp[l-1][jp[l-1][v]];
		
	for (int u : G[v]) if (D[u] > D[v])
	{
		D[u] = D[v] + 1;
		S[D[u]].insert(u);
		parent[u] = min(parent[u], v);
	}
}

int dist(int a, int b)
{
	return D[a] + D[b] - D[lca(a, b)] * 2;
}

int main()
{
	int n, m;
	scanf ("%d%d", &n, &m);
	while (m--)
	{
		int a, b;
		scanf ("%d%d", &a, &b);
		G[a].pb(b);
		G[b].pb(a);
	}
	
	fill(D, D+n, n);
	fill(parent, parent+n, n);
	D[0] = 0;
	disc(0, 0);
	int v = 0;
	long long res = 0;
	FOR(d, 1, n)
	{
		for (int u : S[d])
		{
			res += dist(v, parent[u]) + 2;
			v = parent[u];
			disc(u, parent[u]);
		}
		
		if (S[d].empty())
			break;
		res--;
		v = *(S[d].rbegin());
	}
	
	printf("%lld\n", res);
	return 0;
}