#include <fstream>
#include <vector>

#define DIMN 100010
using namespace std;
int v[DIMN];

struct nod {
    int inf;
    nod *next;
};

nod *L[DIMN], *q;

int n, m, i, x, y, nr;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

void dfs(int x) {
    v[x] = 1;
    for (nod  *q = L[x]; q!=NULL; q = q->next)
        if (v[ q->inf ] == 0)
            dfs(  q->inf  );
}

int main() {
    fin>>n>>m;
    for (i=1;i<=m;i++) {
        fin>>x>>y;
        // pun nod cu inf x in lista y
        q = new nod;
        q->inf = x;
        q->next = L[y];
        L[y] = q;

        q = new nod;
        q->inf = y;
        q->next = L[x];
        L[x] = q;

    }

    for (i=1;i<=n;i++)
        if (v[i] == 0) {
            nr++;
            dfs(i);
        }

    fout<<nr;
    return 0;
}