#include <iostream>
#include <fstream>
#include <queue>
#include <vector>


using namespace std;

ifstream fin ("dfs.in");
ofstream fout ("dfs.out");

vector<int> vec[100005];

bool viz[100005];
int n, m;

void dfs(int x){
    viz[x]=1;
    for(int i: vec[x]){
        if(!viz[i])
            dfs(i);
    }
}

int main()
{
    int sol=0;

    fin>>n>>m;
    for(int i=1; i<=m; i++){
        int x, y;
        fin>>x>>y;
        vec[x].push_back(y);    
        vec[y].push_back(x);    
    }


    for(int i=1; i<=n; i++)
        if(viz[i]==0){
            sol++;
            dfs(i);
        }
    fout<<sol;
    return 0;
}