#include <stdio.h>
#include <stdbool.h>

#define MAX_NODES   100001
#define MAX_EDGES   200001

struct edge_t {
    int node;
    int next;
} edges[MAX_EDGES];

int graph[MAX_NODES], edge_it = 1;
bool vis[MAX_NODES];

int add_edge(int x, int y)
{
    edges[edge_it] = (struct edge_t){y, graph[x]};
    graph[x] = edge_it++;
}

void dfs(int node)
{
    struct edge_t edge = edges[graph[node]];

    vis[node] = true;
    while (edge.node) {
        if (!vis[edge.node])
            dfs(edge.node);

        edge = edges[edge.next]; 
    }
}

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

    int n, m, x, y, sol = 0;
    scanf("%d %d", &n, &m);

    while (m--) {
        scanf("%d %d", &x, &y);
        add_edge(x, y);
        add_edge(y, x);
    }

    for (int i = 1; i <= n; i++) {
        if (!vis[i]) {
            dfs(i);
            sol++;
        }
    }

    printf("%d", sol);

    return 0;
}