#include <fstream>
#include <vector>
#include <algorithm>
#include <set>
#include <bitset>
using namespace std;

ifstream is("dfs.in");
ofstream os("dfs.out");

const int Dim = 1e6 + 1;

int n, m;
vector<int> G[Dim];
int T[Dim], niv[Dim], L[Dim];
bitset S;

pair<int, int> ST[Dim], p;
int sp, K;  // stack pointer, nr comp conexe
set<int> comp[Dim];

void Read();
void Dfs(int x);
void Write();

int main()
{
    Read();
    Dfs(1);

    os << K + 1 << '\n';
    os.close();
    return 0;
}

void Read()
{
    is >> n >> m;
    int x, y;
    S.resize(n+1);
    for( int i = 1; i <= n; ++i )
    {
        is >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    is.close();
}

void Dfs(int x)
{
    S[x] = true;
    L[x] = niv[x];
    for (vector<int>::iterator it = G[x].begin(); it != G[x].end(); ++it)
        if (!S[*it])
        {
            T[*it] = x;
            niv[*it] = niv[x] + 1;
            ST[++sp] = make_pair(x, *it);

            Dfs(*it);

            if (L[*it] >= niv[x])
            {
                ++K;
                while (true)
                {
                    p = ST[sp--];
                    comp[K].insert(p.first);
                    comp[K].insert(p.second);

                    if ( p.first == x && p.second == *it)
                        break;
                }
            }

            L[x] = min(L[x], L[*it]);
        }
        else
            if ( *it != T[x] ) //back edge
				L[x] = min(L[x], niv[*it]);


}