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

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

const int MAX_N = 100010;

vector<int> graf[MAX_N];
bool visited[MAX_N];

int N, M;

void dfs(int node);

int main(int argc, char const *argv[])
{
    fin >> N >> M;
    for (int i = 0; i < M; ++i) {
        int x, y;
        fin >> x >> y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }

    int result = 0;
    for (int i = 1; i <= N; ++i) {
        if (visited[i] == false) {
            ++result;
            dfs(i);
        }
    }
    fout << result;

    return 0;
}

void dfs(int node) {
    visited[node] = true;
    for (int i = 0; i < graf[node].size(); ++i) {
        if (visited[graf[node][i]] == false) {
            dfs(graf[node][i]);
        }
    }
}