#include <bits/stdc++.h>
#define max_n 100001

using namespace std;

vector<int> ad[max_n];
int f[max_n];
void dfs(int nod)
{
    f[nod] = 1;
    for (int i = 0; i < ad[nod].size(); i++)
    {
        if (f[ad[nod][i]] == 0)
            dfs(ad[nod][i]);
    }
}

int main()
{
    ifstream cin("dfs.in");
    ofstream cout("dfs.out");
    int n, m, a, b, i, cnt = 0;
    cin >> n >> m;
    for (i = 0; i < m; i++)
    {
        cin >> a >> b;
        ad[a].push_back(b);
        ad[b].push_back(a);
    }
    for (i = 1; i <= n; i++)
    {
        if (f[i] == 0)
        {
            dfs(i);
            cnt++;
        }
    }
    cout << cnt;
    return 0;
}