#include <iostream>
#include <fstream>
#include <stdint.h>
#include <vector>

const int32_t MAX_N = 100000;

std::vector<int32_t> adj[MAX_N];
bool used[MAX_N];

void DFS(int32_t node) {
    used[node] = true;

    for(int32_t next : adj[node]) {
        if(!used[next])
            DFS(next);
    }
}

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

    int32_t n, m;
    fin >> n >> m;
    for(int32_t i = 0; i != m; ++i) {
        int32_t x, y;
        fin >>x >> y;
        --x; --y;

        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    int32_t compCount = 0;
    for(int32_t i = 0; i != n; ++i) {
        if(!used[i]) {
            DFS(i);
            ++compCount;
        }
    }

    fout << compCount;

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

    return 0;
}