#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define rng(a) a.begin(),a.end()
#define rrng(a) a.rbegin(),a.rend()
#define maxs(x,y) (x = max(x,y))
#define mins(x,y) (x = min(x,y))
#define limit(x,l,r) max(l,min(x,r))
#define lims(x,l,r) (x = max(l,min(x,r)))
#define isin(x,l,r) ((l) <= (x) && (x) < (r))
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define uni(x) x.erase(unique(rng(x)),x.end())
#define snuke srand((unsigned)clock()+(unsigned)time(NULL));
#define show(x) cout<<#x<<" = "<<x<<endl;
#define PQ(T) priority_queue<T,v(T),greater<T> >
#define bn(x) ((1<<x)-1)
#define dup(x,y) (((x)+(y)-1)/(y))
#define newline puts("")
#define v(T) vector<T>
#define vv(T) v(v(T))
typedef long long int ll;
typedef unsigned uint;
typedef unsigned long long ull;
typedef pair<int,int> P;
typedef tuple<int,int,int> T;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<P> vp;
typedef vector<T> vt;
inline int getInt() { int x; scanf("%d",&x); return x;}
template<typename T>inline istream& operator>>(istream&i,v(T)&v)
{rep(j,sz(v))i>>v[j];return i;}
template<typename T>string join(const v(T)&v)
{stringstream s;rep(i,sz(v))s<<' '<<v[i];return s.str().substr(1);}
template<typename T>inline ostream& operator<<(ostream&o,const v(T)&v)
{if(sz(v))o<<join(v);return o;}
template<typename T1,typename T2>inline istream& operator>>(istream&i,pair<T1,T2>&v)
{return i>>v.fi>>v.se;}
template<typename T1,typename T2>inline ostream& operator<<(ostream&o,const pair<T1,T2>&v)
{return o<<v.fi<<","<<v.se;}
template<typename T>inline ll suma(const v(T)& a) { ll res(0); for (auto&& x : a) res += x; return res;}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
const int MX = 200005;
#define dame { puts("-1"); return 0;}
#define yn {puts("Yes");}else{puts("No");}
//---------------------------------------------------------------
#define fastio std::ios::sync_with_stdio(false);
#define myio ifstream iofi; if(argc>1){iofi.open(argv[1]); std::cin.rdbuf(iofi.rdbuf());}
//--------------------------------------------------------------

vvi graph;

int bfs(int v,int n){
  vi visited(n,0);
  queue<int> q;
  q.push(v); visited[v] = true;
  while(!q.empty()){
    int s = q.front(); q.pop();
    rep(i,n){
      if(!graph[s][i]) continue;
      if(visited[i]) continue;
      visited[i] = true;
      q.push(i);
    }
  }  
  int ret = false;
  rep(i,n){
    if(!visited[i]){ret=true;break;}
  }
  return ret;
}

int main(int argc,char** argv){ fastio; myio;
  int n,m;
  cin>>n>>m;
  graph = vvi(n,vi(n,0));
  rep(i,m){
    int a,b;
    cin>>a>>b;
    a--;b--;
    graph[a][b] = true;
    graph[b][a] = true;
  }
  vi visited(n,0);
  int ans = 0;
  rep(i,n) srep(j,i+1,n){ 
    if(graph[i][j]){ 
      graph[i][j] = false;
      graph[j][i] = false;
      
      ans += bfs(0,n);

      graph[i][j] = true;
      graph[j][i] = true;
    }
  }
  cout<<ans;
}

Measured memory_bytes: 256