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

void DFS(int u,std::vector<std::vector<int>> g, std::vector<bool>& visited) {
    std::stack<int> s; 
    s.push(u); 
    visited[u] = true; 

    while (!s.empty()) { 
        int u = s.top(); 
        s.pop(); 

        for (int v : g[u]) { 
            if (!visited[v]) { 
                visited[v] = true; 
                s.push(v); 
            }
        }
    }
}

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

    int n, m;
    fin >> n >> m;

    std::vector<std::vector<int>> g(n+1);
    std::vector<bool> visited(n + 1, false);

    for (int i = 1; i <= m; i++) {
        int u, v;
        fin >> u >> v;
        g[u].push_back(v); 
        g[v].push_back(u); 
    }

    int cnt = 0; 
    for (int i = 1; i <= n; i++) {
        if (!visited[i]) { 
            cnt++; 
            DFS(i,g,visited); 
        }
    }

    fout << cnt;
    return 0;
}