#include <bits/stdc++.h>

using namespace std;

vector <int> graf[100005];
bitset <100005> viz;
int n, m, nrfin;

void dfs(int nod)
{
    viz[nod] = true;
    for (const auto &it : graf[nod])
        if (!viz[it])
        dfs(it);
}

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