#include <stdio.h>

#define NMAX 100000
#define MMAX 200000

static struct edge {
    int v;
    int e;
} edges[2 * MMAX + 1];

static int adj[NMAX + 1], visited[NMAX + 1];

static void dfs(int s)
{
    int i;

    for (i = adj[s]; i != 0; i = edges[i].e) {
        if (!visited[edges[i].v]) {
            visited[edges[i].v] = 1;
            dfs(edges[i].v);
        }
    }
}

int main(void)
{
    int n, m, i, v, u, res;

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

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

    for (i = 1; i <= m; i++) {
        scanf("%d %d", &v, &u);

        edges[2 * i].v = u;
        edges[2 * i].e = adj[v];
        adj[v] = 2 * i;

        edges[2 * i + 1].v = v;
        edges[2 * i + 1].e = adj[u];
        adj[u] = 2 * i + 1;
    }

    res = 0;

    for (i = 1; i <= n; i++) {
        if (!visited[i]) {
            res++;
            visited[i] = 1;
            dfs(i);
        }
    }

    printf("%d", res);

    return 0;
}