#include <iostream>
#include <vector>
#include <stdio.h>
#include <fstream>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
vector<int> a[100002];
int m;int n;
int cant1;
bool viz[100000];
void citire()
{
    in>>n>>m;
    int x,y;
    for(int i =1;i<=m;i++)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}

void dfs(int x)
    {
        int y;
        viz[x] = true;
        for(size_t i=0;i<a[x].size();i++)
        {
            y=a[x][i];
            if(!viz[y])
                dfs(y);
        }
    }

int main()
{
    citire();
    for(int i =1;i<=n;i++)
    {
        if(!viz[i])
        {
            dfs(i);
            cant1++;
        }

    }
    out<<cant1;
    return 0;
}