#include <bits/stdc++.h>
#define INF 10000001
using namespace std;

class Reader {
  public:
    Reader() {}
    Reader(const char *file_name) {
        input_file = fopen(file_name, "r");
        cursor = 0;
        fread(buffer, SIZE, 1, input_file);
    }
    inline Reader &operator >>(int &n) {
        while(buffer[cursor] < '0' || buffer[cursor] > '9') {
            advance();
        }
        n = 0;
        while('0' <= buffer[cursor] && buffer[cursor] <= '9') {
            n = n * 10 + buffer[cursor] - '0';
            advance();
        }
        return *this;
    }
  private:
    FILE *input_file;
    static const int SIZE = 1 << 17;
    int cursor;
    char buffer[SIZE];
    inline void advance() {
        ++ cursor;
        if(cursor == SIZE) {
            cursor = 0;
            fread(buffer, SIZE, 1, input_file);
        }
    }
};

int num_nodes;
int num_edges;
int num_conected_components;
vector<vector <int>> adj(100001);
vector<int> visited(100001);

void dfs(int node) {
    visited[node]=1;
    for(auto next:adj[node])
        if(not visited[next])
            dfs(next);
}

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

    fin>>num_nodes>>num_edges;
    for(int i=1; i<=num_edges; i++) {
        int src,dest;
        fin>>src>>dest;
        adj[src].push_back(dest);
        adj[dest].push_back(src);
    }

    for(int i=1; i<=num_nodes; i++)
        if(not visited[i])
            dfs(i),num_conected_components++;

    fout<<num_conected_components;

    return 0;
}