#include <fstream>
#include <vector>
#include <stack>

using namespace std;

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

vector<vector<unsigned int> > G;
vector<bool> seen;
void dfs(unsigned int start){
    seen[start]=true;

    stack<int> s;
    s.push(start);
    while(!s.empty()){
        int x = s.top();
        s.pop();
        for(unsigned int v:G[x])
            if(!seen[v]){
                seen[v]=true;
                s.push(v);
            }
    }
}

int main() {
    unsigned int n, m;
    fin >> n >> m;
    G = vector<vector<unsigned int> >(n + 1);
    seen = vector<bool>(n + 1, false);

    for (unsigned int i = 0; i < m; i++) {
        unsigned int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    int counter = 0;
    for (unsigned int i = 1; i <= n; i++) {
        if (!seen[i]) {
            dfs(i);
            counter++;
        }
    }
    fout << counter;

    return 0;
}