#include <cstdio>
#include <cmath>
#include <climits>
#include <vector>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <bitset>
#include <map>
#include <cstring>
#include <algorithm>

#define NMAX 100003

using namespace std;

FILE* fin, * fout;

int n, m;
vector<int>graf[NMAX];
bool viz[NMAX];

void dfs(int nod, int prec)
{
	viz[nod] = true;
	for (int i = 0; i < graf[nod].size(); i++)
	{
		int nd = graf[nod][i];
		if (prec != nd)
		{
			dfs(nd, nod);
		}
	}
}

int main()
{
	fin = fopen("dfs.in", "r");
	fout = fopen("dfs.out", "w");
	
	fscanf(fin, "%d %d", &n, &m);
	for (int i = 1; i <= m; i++)
	{
		int x, y;
		fscanf(fin, "%d %d", &x, &y);
		graf[x].push_back(y);
		graf[y].push_back(x);
	}

	int nrc = 0;
	for (int i = 1; i <= n; i++)
	{
		if (!viz[i])
		{
			dfs(i, 0);
			nrc++;
		}
	}
	fprintf(fout, "%d", nrc);
	return 0;
}