#include <iostream>
#include <vector>
#include <queue>

using namespace std;

vector<vector<int>> G;
vector<bool> visited;

int N, M;

void fillgraf(int node) {
    if(!visited[node]) {
        visited[node] = true;
        for(auto x : G[node]) {
            fillgraf(x);
        }
    }
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    cin >> N >> M;
    G.resize(N + 1);
    visited.resize(N  + 1);

    for(int i = 1; i <= M; i++) {
        int x, y;
        cin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    int S = 0;
    for(int i = 1; i <= N; i++) {
        if(!visited[i]) {
            fillgraf(i);
            S++;
        }
    }
    cout << S;
}