#include<iostream>
#include<vector>
#include<string>
#include<algorithm>
#include<cmath>
#include<functional>
#include<map>
#include<cstdlib>
#include<complex>
#include<numeric>
#include<set>
#include<deque>

using namespace std;
using Int = long long;
Int INF = 1LL << 60;
const Int MOD = 1000000000 + 7;

template<int Modulo = MOD> struct Mint {
	Int val;
	constexpr Mint(Int v = 0) noexcept : val(v% Modulo) {
		if (val < 0) v += Modulo;
	}
	constexpr int getmod() { return Modulo; }
	constexpr Mint operator - () const noexcept { return val ? Modulo - val : 0; }
	constexpr Mint operator + (const Mint& r) const noexcept { return Mint(*this) += r; }
	constexpr Mint operator - (const Mint& r) const noexcept { return Mint(*this) -= r; }
	constexpr Mint operator * (const Mint& r) const noexcept { return Mint(*this) *= r; }
	constexpr Mint operator / (const Mint& r) const noexcept { return Mint(*this) /= r; }
	constexpr Mint& operator += (const Mint& r) noexcept {
		val += r.val;
		if (val >= Modulo) val -= Modulo;
		return *this;
	}
	constexpr Mint& operator -= (const Mint& r) noexcept {
		val -= r.val;
		if (val < 0) val += Modulo;
		return *this;
	}
	constexpr Mint& operator *= (const Mint& r) noexcept {
		val = val * r.val % Modulo;
		return *this;
	}
	constexpr Mint& operator /= (const Mint& r) noexcept {
		Int a = r.val, b = Modulo, u = 1, v = 0;
		while (b) {
			Int t = a / b;
			a -= t * b; swap(a, b);
			u -= t * v; swap(u, v);
		}
		val = val * u % Modulo;
		if (val < 0) val += Modulo;
		return *this;
	}
	constexpr bool operator == (const Mint& r) const noexcept {
		return this->val == r.val;
	}
	constexpr bool operator != (const Mint& r) const noexcept {
		return this->val != r.val;
	}
	friend ostream& operator << (ostream& os, const Mint<Modulo>& x) noexcept {
		return os << x.val;
	}
	friend istream& operator >> (istream& is, Mint<Modulo>& x) noexcept {
		Int tmp; is >> tmp;
		x = Mint<Modulo>(tmp);
		return is;
	}
	friend constexpr Mint<Modulo> modpow(const Mint<Modulo>& a, Int n) noexcept {
		Mint res(1), tmp = a;
		while (n > 0) {
			if (n & 1) res *= tmp;
			tmp *= tmp;
			n >>= 1;
		}
		return res;
	}
};

using mint = Mint<>;

Int N;

void dfs(vector<vector<bool>>& graph,vector<bool>& seen,Int v) {
	seen[v] = true;

	for (Int i = 0; i < N;i++) {
		if (graph[v][i] == false)continue;
		if (seen[i] == true)continue;
		dfs(graph,seen,i);
	}

}

int main() {

	cin.tie(nullptr);
	ios::sync_with_stdio(false);

	Int M;
	cin >> N >> M;

	vector<Int> a(M);
	vector<Int> b(M);

	vector<vector<bool>> graph(N, vector<bool>(N, false));
	vector<bool> seen(N);

	Int tempa, tempb;
	for (Int i = 0; i < M; i++) {
		cin >> tempa >> tempb;
		tempa--;
		tempb--;//0-indexed
		a[i] = tempa;
		b[i] = tempb;
		graph[tempa][tempb] = graph[tempb][tempa] = true;
	}

	Int ans = 0;
	for (Int i = 0; i < M; i++) {
		graph[a[i]][b[i]] = graph[b[i]][a[i]]=false;

		for (Int i = 0; i < N; i++) {
			seen[i] = false;
		}

		dfs(graph,seen,0);

		bool temp = true;
		for (Int j = 0; j < N; j++) {
			if (seen[j] == false) {
				temp = false;
				break;
			}
		}
		
		if (temp == false)ans++;
		graph[a[i]][b[i]] = graph[b[i]][a[i]] = true;

	}

	cout << ans << "\n";

}

Measured memory_bytes: 256