//#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
vector<int> v[100005];
bool ajuns[100005];
int cnt=0;
void dfs(int nod){
    ajuns[nod]=1;
    for(int i=0;i<v[nod].size();i++){
        if(ajuns[v[nod][i]]==0)
            dfs(v[nod][i]);
    }
}
int main()
{
    /*cin>>n>>m;
    for(int i=1;i<=m;i++){
        cin>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);

    }
    */
    int n,m,a,b;
    cin>>n>>m;
    for(int i=1;i<=m;i++){
        cin>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(int i=1;i<=n;i++){
        if(ajuns[i]==0){
            dfs(i);
            cnt++;
        }
    }
    cout<<cnt;
    return 0;
}