#include <vector>
#include <iostream>
#include <cstdio>
#include <cstring>
#define maxn 10005

using namespace std;

int a[maxn][maxn], n, m, viz[maxn];

void DFS(int nod)
{
	int i;
	viz[nod] = 1;
	for (i = 1; i <= n; i++)
    {
        if(!viz[i] && a[nod][i]) DFS(i);
    }
}

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

    cin >> n >> m;
    int i, x, y, cnt = 0;

    for(i = 1; i <= m; i++)
    {
        cin >> x >> y;
        a[x][y] = a[y][x] = 1;
    }

	for (i = 1; i <= n; i++)
    {
        if(!viz[i])
        {
            cnt++; DFS(i);
        }
    }
	cout << cnt;
	return 0;
}