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

using namespace std;

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

vector <int> v[100005];

int n,m;
bool b[100005];

void dfs(int x){
    b[x]=true;
    for(int i=0;i<v[x].size();i++){
        if(!b[v[x][i]]){
            dfs(v[x][i]);
        }
    }
    return;
}

int main()
{
    fin>>n>>m;
    int r=0,x,y;
    for(int i=0;i<m;i++){
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++){
        if(!b[i]){
            dfs(i);
            r++;
        }
    }
    fout<<r;
    return 0;
}