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

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<>;

class UnionFind {
private:
	vector<Int> data;

public:
	Int root(Int x) { return data[x] < 0 ? x : data[x] = root(data[x]); }
	UnionFind(Int size) : data(size, -1) { }
	bool same(Int x, Int y) { return root(x) == root(y); }
	Int size(Int x) { return -data[root(x)]; }

	bool unite(Int x, Int y) {
		x = root(x); y = root(y);
		if (x != y) {
			if (data[y] < data[x]) swap(x, y);
			data[x] += data[y]; data[y] = x;
			return true;
		}
		else {
			return false;
		}
	}
};

int main() {

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

	Int N, M;
	cin >> N >> M;

	vector<Int> a(M), b(M);
	for (Int i = 0; i < M; i++) {
		cin >> a[i] >> b[i];
		a[i]--;
		b[i]--;
	}

	Int ans = 0;
	Int temp;
	for (Int i = 0; i < M; i++) {//組み合わせiを繋げない場合
		UnionFind tree(N);
		for (Int j = 0; j < M; j++) {
			if (i == j)continue;
			tree.unite(a[j], b[j]);
		}

		temp = tree.root(0);
		//根が一個でも異なるとout
		for (Int j = 1; j < N; j++) {
			if (temp != tree.root(j)) {
				ans++;
				break;
			}
		}
	}

	cout << ans << "\n";

}

Measured memory_bytes: 256