#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector<vector<int>>g;
vector<bool>viz;
int n,m;
void read()
{
    int x,y;
    fin>>n>>m;
    g=vector<vector<int>>(n+1);
    viz=vector<bool>(n+1);
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
}
void DFS(int np)
{
    viz[np]=1;
    for(auto e:g[np])
        if(!viz[e])
            DFS(e);
}
int main()
{
    int nrc=0;
    read();
    for(int i=1; i<=n; i++)
    {
        if(!viz[i])
        {
            nrc++;
            DFS(i);
        }
    }
    fout<<nrc;
}