#include <cstdio>
#include <vector>

using namespace std;

int n, m;
vector<int> vecini[100005];
int viz[100005];

void citire()
{
	scanf("%d %d", &n, &m);

	int tmp1, tmp2;

	for(int i = 0; i < m; i++)
	{
		scanf("%d %d", &tmp1, &tmp2);

		tmp1--;
		tmp2--;

		vecini[tmp1].push_back(tmp2);
		vecini[tmp2].push_back(tmp1);
	}
}

void dfs(int x)
{
	viz[x] = true;

	int l = vecini[x].size();

	for(int i = 0; i < l; i++)
	{
		if(viz[vecini[x][i]] == false)
		{
			dfs(vecini[x][i]);
		}
	}
}

void solve()
{
	int nr = 0;

	for(int i = 0; i < n; i++)
	{
		if(viz[i] == false)	
		{
			dfs(i);
			nr++;
		}
	}

	printf("%d", nr);
}

int main()
{
	freopen("dfs.in", "r", stdin);
	freopen("dfs.out", "w", stdout);

	citire();
	solve();

	return 0;
}