#include<bits/stdc++.h>
#define NMAX 100005

using namespace std;

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


int N , M , x, y , cnt;
vector <int> G[NMAX];

bool v[NMAX];

void dfs(int nod){
    v[nod] = true;
    for(auto i: G[nod]){
        if(!v[i]) {
            
            dfs(i);
        }
    }
}

int main(){
    
    fin >> N >> M;
    for(int i = 1; i <= M; i++){
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    
    for(int i = 1; i <= N; i++){
        if(!v[i]){
            cnt++;
            dfs(i);
        }
    }
    fout << cnt;
    return 0;
}