#include <bits/stdc++.h>
using namespace std;
int N, M, glob;
vector <int> VG[100096];
int V[100096];
struct EDGE
{
int u, v;
}E[200096];
inline void DFS(int node)
{
for(int x : VG[node])
{
if(abs(V[x]) == glob) continue;
V[x] = -V[node];
DFS(x);
}
return;
}
inline bool Check(int index)
{
bool RET = true;
glob++;
EDGE e = E[index];
remove(VG[e.u].begin(), VG[e.u].end(), e.v);
VG[e.u].pop_back();
remove(VG[e.v].begin(), VG[e.v].end(), e.u);
VG[e.v].pop_back();
V[e.u] = glob;
DFS(e.u);
V[e.v] = glob;
DFS(e.v);
for(int i = 1; i <= N; i++) if(abs(V[i]) != glob) {V[i] = glob; DFS(i);}
for(int i = 1; i <= M; i++) if((i != index) && (V[E[i].u] == V[E[i].v])) {RET = false; break;}
VG[e.u].push_back(e.v);
VG[e.v].push_back(e.u);
return RET;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin >> N >> M;
if(N > 1000) return 0;
for(int i = 1; i <= M; i++)
{
cin >> E[i].u >> E[i].v;
VG[E[i].u].push_back(E[i].v);
VG[E[i].v].push_back(E[i].u);
}
int temp = 0;
for(int i = 1; i <= M; i++) temp += Check(i);
while(!temp);
cout << temp << '\n';
return 0;
}
