#include <iostream>
#include <fstream>
#include <queue>
#include <bitset>
#include <vector>

#define maxSize 100001

using namespace std;

vector<vector<int>> readAdjacencyList(ifstream &fin, int nodes, int edges, bool isDirected = false) {
    vector<vector<int>> adjList(nodes + 1);
    for (int i = 0; i < edges; i++) {
        int x, y;
        fin >> x >> y;
        adjList[x].push_back(y);
        if (!isDirected) {
            adjList[y].push_back(x);
        }
    }
    return adjList;
}

bitset<maxSize> marked;

void depthFirstSearch(const vector<vector<int>>& adjList, int node) {
    marked[node] = true;

    for (auto neighbor : adjList[node]) {
        if (!marked[neighbor]) {
            depthFirstSearch(adjList, neighbor);
        }
    }
}

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

    int components = 0;
    int nodes, edges;
    fin >> nodes >> edges;

    auto adjList = readAdjacencyList(fin, nodes, edges);

    for (int i = 1; i <= nodes; i++) {
        if (marked[i] == false) {
            depthFirstSearch(adjList, i);
            components++;
        }
    }

    fout << components << endl;

    fin.close();
    fout.close();

    return 0;
}