#include <stdio.h>
#include <vector>
typedef std::vector<int> Graph;

void dfs(Graph graph[], int nod, int viz[])
{
    viz[nod] = 1;
    for (int it = 0; it < graph[nod].size(); it++)
    {
        int i = graph[nod][it];
        if (!viz[i])
            dfs(graph, i, viz);
    }
}

int main()
{
    FILE *in = fopen("dfs.in", "r");
    FILE *out = fopen("dfs.out", "w");
    int n, m;
    fscanf(in, "%d%d", &n, &m);
    Graph *graph = new Graph[n];
    for (int i = 0; i < m; i++)
    {
        int nod1, nod2;
        fscanf(in, "%d%d", &nod1, &nod2);
        nod1--;
        nod2--;
        graph[nod1].push_back(nod2);
        graph[nod2].push_back(nod1);
    }
    int *viz = new int[n]();
    int nr = 0;
    for (int i = 0; i < n; i++)
    {
        if (!viz[i])
        {
            dfs(graph, i, viz);
            nr++;
        }
    }
    fprintf(out, "%d\n", nr);
    delete viz;
    delete[] graph;
    fclose(in);
    fclose(out);
    return 0;
}