#include <iostream>
#include <cstdio>
#include <vector>

using namespace std;

#define N_MAX 100000

vector<int>graf[N_MAX+1];
int n,m;


void citire()
{
    scanf("%d %d ",&n,&m);
    for(int i=1;i<=m;i++)
    {
        int x,y;
        scanf("%d %d ",&x,&y);
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
}

bool viz[N_MAX+1];
void dfs(int nod)
{
    viz[nod]=true;
    int len=graf[nod].size();
    for(int i=0;i<len;i++)
    {
        if(!viz[graf[nod][i]])
            dfs(graf[nod][i]);
    }
}
void rezolvare()
{
    int nr_con=0;
    for(int i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            dfs(i);
            nr_con++;
        }
    }
    printf("%d\n",nr_con);
}

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

    citire();
    rezolvare();
    return 0;
}