#define DM 100001
#include <fstream>
#include <vector>
using namespace std;

ifstream fi ("dfs.in");
ofstream fo ("dfs.out");
int n, m, a, b, cmp[DM];
vector <int> v[DM];

void dfs(int x, int val)
{
	cmp[x] = val;
	for (auto i:v[x])
		if (!cmp[i])
			dfs(i, cmp[x]);
}

int main()
{
	fi >> n >> m;
	for (int i = 1; i <= m; ++i)
	{
		fi >> a >> b;
		v[a].push_back(b);
		v[b].push_back(a);
	}
	for (int i = 1; i <= n; ++i)
		if (!cmp[i])
			dfs(i, ++cmp[0]);
	fo << cmp[0];
	return 0;
}