#include <fstream>
#include <iostream>
#include <set>
using namespace std;

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

set<int> a[100001];
int cc, viz[100001];

void dfs(int x){
    viz[x] = 1;
    for(int k : a[x]){
        if(viz[k] == 0)
            dfs(k);
    }
}

int main(){
    int n, m;
    in >> n >> m;
    while(m--){
        int x, y;
        in >> x >> y;
        a[x].insert(y);
        a[y].insert(x);
    }

    for(int i=1; i<=n; i++){
        if(viz[i] == 0){
            cc++;
            dfs(i);
        }
    }
    out << cc;
}