#include <bits/stdc++.h>
#define NMAX 100005
using namespace std;

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

int n,m,x,y, ans;
bool viz[NMAX];
vector<int>g[NMAX];

void dfs(int nod){
    viz[nod] = 1;
    for(int i=0; i < g[nod].size(); ++i)
    {
        int vecin = g[nod][i];
        if(!viz[vecin])
            dfs(vecin);
    }
}

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

    for(int i=1; i<=n; ++i)
        if(!viz[i])
        {
            ans++;
            dfs(i);
        }
}

int main(){
    citire();
    fout << ans;
}