#include <bits/stdc++.h>
#define NMAX 100100

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

void citire();
void DFS(int x);
vector <int> G[NMAX];

bool uz[NMAX];
int n, m, c;

int main(){
    int i;
    citire();
    for(i=1;i<=n;i++)
        if(!uz[i]){
        c++;
        DFS(i);
    }
    fout << c;
}

void citire(){
    int i, x, y;
    fin >> n >> m;
    for(i=0;i<m;i++){
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);

    }
}

void DFS(int x){
    int i;
    uz[x] = 1;
    for(i=0;i<G[x].size();i++)
        if(!uz[G[x][i]]) DFS(G[x][i]);
}