#include <bits/stdc++.h>
using namespace std;
int n, m, i, j, x, y, nr;
vector <int> v[100005];
bool viz[100005];
void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0;i<v[nod].size();i++)
        if(!viz[v[nod][i]])
        dfs(v[nod][i]);
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    cin>>n>>m;
    for(i=1;i<=m;i++)
    {
        cin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(!viz[i])
    {
        nr++;
        dfs(i);
    }
    cout<<nr;
    return 0;
}