#include <cstdio>
#include <vector>
#include <fstream>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> vct[100002];
int vis[100001], k, x, y, m, n, i;

void DFS(int a){
    int i;
    vis[a]=1;
    for(i=0; i<vct[a].size(); ++i)
        if(!vis[vct[a][i]])
            DFS(vct[a][i]);
}
int main(){
    fin>>n>>m;
    for(i=1; i<=m; i++){
        fin>>x>>y;
        vct[x].push_back(y);
        vct[y].push_back(x);
    }
    for(i=1; i<=n; ++i)
        if(!vis[i]){
            k++;
            DFS(i);
        }
    fout<<k;
    return 0;
}