#include<bits/stdc++.h>
#define fi first
#define sc second
#define ll long long
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n, m, ans;
vector<int>v[200001];
bool viz[100001];
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()
{
    f>>n>>m;
    for(int i=1; i<=m; i++)
    {
        int x, y;
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
    {
        if(!viz[i])
        {
            ans++;
            dfs(i);
        }
    }
    g<<ans;
    return 0;
}