#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;
vector<int> v[100001];
int use[100001];

void dfs(int poz)
{
    use[poz] = 1;
    for(int i=0;i<v[poz].size();i++)
    {
        if(use[v[poz][i]]==0)
        {
            dfs(v[poz][i]);
        }

    }
    return;
}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int n,i,j,m,k=0;
    cin>>n>>m;
    for(int x=1;x<=m;x++)
    {
        cin>>i>>j;
        v[i].push_back(j);
        v[j].push_back(i);
    }
    for(i=1;i<=n;i++)
    {
        if(use[i]==0)
            dfs(i),k++;
    }
    cout<<k;
    return 0;
}