# include<cstdio>
# include<vector>

using namespace std;

vector <int> v[100010];
int n, m, a, b, fr[1000010], c;

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

int main ()
{
	freopen ("dfs.in", "r", stdin );
	freopen ("dfs.out", "w", stdout);
	scanf ("%d%d", &n, &m);
	for ( int i = 1; i<= m; i++)
	{
		scanf ("%d%d", &a, &b);
		v[a].push_back(b);
		v[b].push_back(a);
	}
	for (int i = 1; i<= n; i++)
		if ( !fr[i])
		{
			c++;
			dfs (i);
		}
	printf("%d", c);
	return 0;
}