#include <bits/stdc++.h>
#define NMAX 100005
#define inf (1 << 30)
using namespace std;

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

int n, m, cnt;
bool viz[NMAX];
vector <int> v[NMAX];


void read(){
    fin>>n>>m;

    for(int i=1;i<=m;i++){
        int x, y;
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

}

void dfs(int nod){
    viz[nod] = 1;

    for(auto & it: v[nod]){
        if(!viz[it]){
            dfs(it);
        }
    }
}

int main(){
    read();
    for(int i=1;i<=n;i++){
        if(!viz[i]){
            dfs(i);
            cnt++;
        }
    }
    fout<<cnt;
    return 0;
}