#include <iostream>
#include <fstream>
#include <vector>
#include <stack>
using namespace std;
int n,m,v[100005];
int nr=0;
vector <vector <int> > graph;
void dfs(int vertex)
{
    v[vertex]=1;
    int i;
    for(i=0;i<graph[vertex].size();i++)
        if(v[graph[vertex][i]]==0)
            dfs(graph[vertex][i]);
}
int main()
{
    int i,a,b;
    ifstream f("dfs.in");
    f>>n>>m;
    graph.resize(n+1);
    for(i=0;i<m;i++)
        {
            f>>a>>b;
            a--;
            b--;
            graph[a].push_back(b);
            graph[b].push_back(a);
        }
    for(i=0;i<n;i++)
        v[i]=0;
    for(i=0;i<n;i++)
        if(v[i]==0)
            nr++,dfs(i);
    ofstream g("dfs.out");
    g<<nr;
    return 0;
}