#include <fstream>
#include <vector>
using namespace std;
int n,m,x,y,nc;
int v[100011];

vector<int> L[100010];


void dfs(int nod) {
	v[nod] = 1;
	for (int i = 0;i<L[nod].size();i++)
		if (v[  L[nod][i]   ] == 0)
			dfs(L[nod][i]);
	
}

int main() {
	ifstream fin("dfs.in");
	ofstream fout("dfs.out");
	register int i,j;
	
	fin>>n>>m;
	for (i=1;i<=m;i++) {
		fin>>x>>y;
		L[x].push_back(y);
		L[y].push_back(x);
//		a[x][y] = a[y][x] = 1;
	}
	for (i=1;i<=n;i++)
		if (v[i] == 0) {
			dfs(i);
			nc++;
		}
	fout<<nc;
	return 0;
}