#include <cstdio>
#include <vector>
using namespace std;

vector <int> noduri[100001];

int n, m, x, y, nr, vizitat[100001], comp[100001];

void dfs(int x)
{
    if(vizitat[x]) return;
    vizitat[x] = 1;
    comp[x] = nr;
    for(int i = 0; i < noduri[x].size(); ++i) {
        dfs(noduri[x][i]);
    }
}

int main()
{
    int i;
    freopen ("dfs.in", "r", stdin);
    freopen ("dfs.out", "w", stdout);
    scanf("%d %d", &n, &m);
    for(i = 1; i <= m; ++i) {
        scanf("%d %d", &x, &y);
        noduri[x].push_back(y);
        noduri[y].push_back(x);
    }
    for(i = 1; i <= n; ++i) {
        if(!vizitat[i]) {
            ++nr;
            dfs(i);
        }
    }
    printf("%d\n", nr);
   /* for(i = 1; i <= n; ++i)
        printf("%d ", comp[i]);*/
    return 0;
}