#include <bits/stdc++.h>
using namespace std;
const int N=1e6;
vector<int> graph[N]; int n,m;bool visited[N];
void dfs(int s)
{
    if(visited[s]) return;
    visited[s]=1;
    for(auto u:graph[s]) dfs(u);
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    cin>>n>>m;int x,y;
    while(m--)
    {
        cin>>x>>y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    int nr=0;
    for(int i=1;i<=n;i++)
    {
        if(!visited[i]) nr++,dfs(i);
    }
    cout<<nr<<"\n";
    return 0;
}