#include <iostream>
#include <stdio.h>
#include <vector>

using namespace std;

vector <int> g[100010];
int viz[100010],n,m;

void citire()
{
    freopen("dfs.in","r",stdin);
    scanf("%d %d",&n,&m);
    for(int i=0;i<m;i++)
    {
        int x,y;
        scanf("%d %d",&x,&y);
        g[x].push_back(y);
        g[y].push_back(x);
    }
}



void dfs(int k)
{
    for(int i=0;i<g[k].size();i++)
    {
        if(!viz[g[k][i]])
        {
            viz[g[k][i]]=1;
            dfs(g[k][i]);
        }
    }
}

int cc=0;
int main()
{
    freopen("dfs.out","w",stdout);
    citire();
    for(int i=0;i<n;i++)
        if(!viz[i])
        {
            cc++;
            dfs(i);
        }
    printf("%d",cc);
    return 0;
}