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

using namespace std;

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

int comp;
bool viz[100001];
vector < int > v[100001];

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

int main()
{
    int N,M,x,y;
    f >> N >> M;
    for(int i = 1; i <= M; i++){
        f >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i = 1; i <= N; i++){
        if(viz[i] == 0){
            dfs(i);
            comp++;
        }
    }
    g << comp;
    return 0;
}