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

using namespace std;

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

vector <int> v[100001];

int n,m,nr;

bool viz[100001];

void dfs(int x)
{
    viz[x]=true;
    for(auto y:v[x]){
        if(!viz[y])
            dfs(y);
    }
}

int main()
{
    in>>n>>m;
    for(int i=0;i<m;i++){
        int x,y;
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(!viz[i]){
            nr++;
            dfs(i);
        }
    out<<nr;
    return 0;
}