#include <fstream>
#include <vector>
#include <bitset>

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

const int nmax = 1e5;

std::bitset<nmax> vis;
std::vector<std::vector<int>> graf;

int n, m;

void dfs(int nod) {
    vis[nod] = 1;
    for(int i : graf[nod])
	if(!vis[i])
	    dfs(i);
}

int main() {
    fin >> n >> m;
    graf.assign(n, std::vector<int>());

    for(int i = 0; i < m; ++i) {
	int x, y;
	fin >> x >> y;
	x--, y--;
	graf[x].emplace_back(y);
	graf[y].emplace_back(x);
    }

    int res = 0;
    for(int i = 0; i < n; ++i)
	if(!vis[i]) {
	    dfs(i);
	    res++;
	}

    fout << res;

    graf.clear();
    fin.close();
    fout.close();
}