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

using namespace std;

const int N = 100001;

int n,m;
bool viz[N];
vector<int> a[N];

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

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int i,j,k,nr=0;
    scanf("%d %d",&n,&m);
    for(k=1;k<=m;k++)
    {
        scanf("%d %d",&i,&j);
        a[i].push_back(j);
        a[j].push_back(i);
    }
    for(i=1;i<=n;i++)
        if(!viz[i])
        {
            nr++;
            dfs(i);
        }
    printf("%d",nr);
    return 0;
}