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

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

vector<int> g[100005];
int n, m, cc[100005];

void citire() {
    fin >> n >> m;
    while(m--) {
        int x, y;
        fin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
}


void dfs(int x, int comp) {
    cc[x] = comp;
    for(auto next: g[x])
        if(!cc[next])
            dfs(next, comp);
}

void solve() {
    int currComp = 0;
    for(int i = 1; i <= n; i++)
        if(!cc[i]) {
            currComp++;
            dfs(i, currComp);
        }
    fout << currComp << '\n';
}

int main() {
    citire();
    solve();
}