# include <bits/stdc++.h>

using namespace std;

const int Nmax = 1e5 + 5;

int n, m, i, nr, x, y;
bool ap[Nmax];

vector <int> G[Nmax];

void dfs(int x)
{
    ap[x] = true;

    for (auto &it: G[x])
        if (!ap[it]) dfs(it);
}

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

    scanf("%d %d\n", &n, &m);

    for (i = 1; i <= m; ++i)
    {
        scanf("%d %d\n", &x, &y);
        G[x].push_back(y), G[y].push_back(x);
    }

    for (i = 1; i <= n; ++i)
    {
        if (!ap[i]) dfs(i), ++nr;
    }

    printf("%d\n", nr);

    return 0;
}