#include <fstream>
#include <vector>

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

int n, m, nr, viz[100001];
std::vector<int> v[100001]; 

void dfs(int nod) {
    viz[nod] = 1;
    for (int vecin : v[nod])
        if (!viz[vecin])
            dfs(vecin);
}

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

    for (int i = 1; i <= n; i++)
        if (!viz[i]) {
            nr++;
            dfs(i);
        }
    
    fout << nr;
    return 0;
}