#include <iostream>
#include <vector>
#include <stack>
#include <fstream>
using namespace std;


vector < vector<int> > graph;
vector <bool> visited;
int n,m,c;

void dfs(int vertex)
{
    if(vertex < 0 || vertex>n-1) return;
    stack<int> s;
    int element,i;
    bool found;

    s.push(vertex);
    visited[vertex]=true;
    while(!s.empty()) {
        element=s.top();
        found=false;
        for(i=0;i<graph[element].size() && !found;i++)
            if(!visited[graph[element][i]]) found=true,c++;
        if(found) {
            i--;
            s.push(graph[element][i]);
            visited[graph[element][i]]=true;
        }
        else  s.pop();
    }
}

int main()
{
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    int x,y;
    f>>n>>m;
    graph.resize(n);
    visited.resize(n,false);
    for(int i=0; i<m; i++) {
        f>>x>>y;
        x--;
        y--;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    c=0;
    for(int i=0; i<visited.size() && i<n;i++)
        if(!visited[i]) dfs(i);
    cout<<c;
    return 0;
}