#include "bits/stdc++.h"
#include <sys/timeb.h>
#include <fstream>

using namespace std;

#define repr(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define rep(i,n) repr(i,0,n)
#define reprrev(i,a,b) for(int i=(int)(b)-1;i>=(int)(a);i--)
#define reprev(i,n) reprrev(i,0,n)
#define repi(itr,ds) for(auto itr=ds.begin();itr!=ds.end();itr++)
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
#define mp make_pair
#define mt make_tuple
#define INF 1050000000
#define INFL 1100000000000000000LL
#define EPS (1e-10)
#define MOD 1000000007
#define PI 3.1415926536
#define RMAX 4294967295

typedef long long ll;
typedef pair<int, int> Pi;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<bool> vb;
typedef vector<char> vc;
typedef vector<string> vs;
typedef vector<double> vd;
typedef vector<Pi> vPi;
typedef vector<vector<int> > vvi;
typedef vector<vector<bool> > vvb;
typedef vector<vector<ll> > vvll;
typedef vector<vector<char> > vvc;
typedef vector<vector<string> > vvs;
typedef vector<vector<double> > vvd;
typedef vector<vector<Pi> > vvPi;
typedef priority_queue<int, vector<int>, greater<int> > pqli;
typedef priority_queue<ll, vector<ll>, greater<ll> > pqlll;
typedef priority_queue<Pi, vector<Pi>, greater<Pi> > pqlP;
struct Edge {
	int from, to, cost;
	bool operator<(Edge e) {
		return cost < e.cost;
	}
};
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;
template <class T>
using vec = vector<T>;
template<class T>
using pql = priority_queue<T, vector<T>, greater<T>>;
string debug_show(Pi a) {
	return "(" + to_string(a.first) + "," + to_string(a.second) + ")";
}

template<class T>
struct augEdge {
	T from, to;
	int cost;
	bool operator<(augEdge e) { return cost < e.cost; }
	bool operator>(augEdge e) { return cost > e.cost; }
};
template<class T>
using augGraph = vector<augEdge<T>>;


class UnionFind {
public:
	vector<int> par, rank, _size;

	UnionFind(int n) {
		par = vector<int>(n);
		rank = vector<int>(n);
		_size = vector<int>(n);
		for (int i = 0; i < n; i++) {
			par[i] = i;
			rank[i] = 0;
			_size[i] = 1;
		}
	}

	// 木の根を求める
	int find(int x) {
		if (par[x] == x) {
			return x;
		}
		else {
			return par[x] = find(par[x]);
		}
	}

	// xとyの属する集合を併合
	void unite(int x, int y) {
		x = find(x);
		y = find(y);
		if (x == y)return;

		if (rank[x] < rank[y]) {
			par[x] = y;
			_size[y] += _size[x];
		}
		else {
			par[y] = x;
			_size[x] += _size[y];
			if (rank[x] == rank[y])rank[x]++;
		}
	}

	// xとyが同じ集合に属するか否か
	bool same(int x, int y) {
		return find(x) == find(y);
	}

	int size(int x) {
		return _size[find(x)];
	}
};

bool isBridge(Graph G, int a, int b) {
	int num = G.size();
	UnionFind uf(num);
	int conn = num;
	rep(i, num) {
		for (auto e : G[i]) {
			if ((e.from == a&&e.to == b) || (e.from == b&&e.to == a))continue;
			if (!uf.same(e.from, e.to)) {
				conn--;
				uf.unite(e.from, e.to);
			}
		}
	}
	if (conn == 1) return false;
	else return true;
}

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int N, M;
	cin >> N >> M;
	Graph G(N);
	rep(i, M) {
		int a, b;
		cin >> a >> b;
		a--; b--;
		G[a].push_back(Edge{ a,b,1 });
		G[b].push_back(Edge{ b,a,1 });
	}

	int ans = 0;
	rep(i, N) {
		for (auto e : G[i]) {
			if (isBridge(G, e.from, e.to))ans++;
		}
	}

	cout << ans / 2 << endl;
	return 0;
}

Measured memory_bytes: 256