#include <iostream>
#include <cstdio>
#include <vector>
#include <bitset>
#define N 100005

using namespace std;

int n,m;

bitset <N> viz;

vector <int> G[N];

void dfs(int x)
{
    viz[x]=1;
    vector <int> ::iterator it;

    for(it=G[x].begin(); it!=G[x].end(); ++it)
    {
        if(viz[*it]==0)
        {
            dfs(*it);
        }
    }
}

int numarare()
{
    int nr=0;
    for(int i=1; i<=n; i++)
    {
        if(viz[i]==0)
        {
            dfs(i);
            nr++;
        }
    }
    return nr;
}

void citire()
{
    scanf("%d %d\n",&n,&m);
    for(int i=0; i<m; i++)
    {
        int x,y;
        scanf("%d %d\n",&x,&y);

        G[x].push_back(y);
        G[y].push_back(x);
    }

    printf("%d",numarare());
}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);

    citire();

    return 0;
}