#include <iostream>
#include <fstream>
#include <bitset>
#include <queue>
using namespace std;

const int N= 100000;
bitset <N+1> viz;
vector <int> a[N+1];

void dfs(int x){
    viz[x]= 1;
    for(auto y: a[x]){
        if(!viz[y]){
            dfs(y);
        }
    }
}

int main()
{
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    int n, m, nc= 0;
    in>>n>>m;

    for(int i= 0; i<m; i++){
        int x, y;
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }

    for(int i= 1; i<=n; i++){
        if(!viz[i]){
            nc++;
            dfs(i);
        }
    }
    out << nc;
    in.close();
    out.close();
    return 0;
}