#include <fstream>
#include <vector>
#define DIM 100010

using namespace std;

vector<int> L[DIM];

int v[DIM], n, m, x, y, i, cc;

ifstream f("dfs.in");
ofstream g("dfs.out");

void dfs(int nod) {
    v[nod] = 1;
    for (int i=0;i<L[nod].size(); i++) {
        int vec = L[nod][i];
        if (v[vec] == 0)
            dfs(vec);
    }
}

int main() {
    f>>n>>m;
    for (i=1;i<=m;i++) {
        f>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }

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