#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

const int MAXN = 100005;

vector<int> graf[MAXN];
bool vis[MAXN];

void dfs(int pos){
    if(vis[pos])
        return;
    for(int i = 0; i < int(graf[pos].size()); ++i){
        if(!vis[graf[pos][i]]){
            vis[graf[pos][i]] = 1;
            dfs(graf[pos][i]);
        }
    }
    return;
}

int main()
{
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    int n, m;
    fin >> n >> m;
    int x, y;
    for(int i = 1; i <= m; ++i){
        fin >> x >> y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    int cnt = 0;
    for(int i = 1; i <= n; ++i){
        if(!vis[i]){
            cnt++;
            dfs(i);
        }
    }
    fout << cnt;
    return 0;
}