#include<stdio.h>
#include<vector>

using namespace std;
#define pb push_back

#define vecb vector<vector<int>>

int n, m;
void citire(vecb &a)
{
	for (int i = 1; i <= m; i++)
	{
		int x, y;
		scanf("%d %d", &x, &y);

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

void dfs(vecb &a, vector<int> &b, int x)
{
	b[x] = 1;
	for (int i = 0; i < a[x].size(); i++)
	{
		if (b[a[x][i]] == 0)
		{
			dfs(a, b, a[x][i]);
		}
	}
}
int solve(vecb &a)
{
	vector<int>b(n + 1);
	int counter = 0;


	for (int i = 1; i <= n; i++)
	{
		if (b[i] == 0)
		{
			counter++;
			dfs(a, b, i);
		}
	}

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


	scanf("%d %d", &n, &m);

	vecb a(n+1, vector<int>(0));

	citire(a);

	printf("%d\n", solve(a));


	return 0;
}