#include <bits/stdc++.h>
using namespace std;

const int MAXN = 1e5 + 2;
vector <int> g[MAXN];
bool seen[MAXN];


void dfs(int node){

    seen[node] = 1;
    for(auto x : g[node])
        if(!seen[x]) dfs(x);

}


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

int main()
{
    int n, m, cnt = 0; fin >> n >> m;
    for(int i = 1; i <= m; ++i){
        int x, y; fin >> x >> y;

        g[x].push_back(y);
        g[y].push_back(x);
    }

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