#include <bits/stdc++.h>

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

int n, m;
std::vector<int> nb[100001];
int viz[100001];

void dfs(int node)
{
    viz[node] = 1;
    for(int i = 0; i < nb[node].size(); i++)
        if(viz[nb[node][i]] == 0)
            dfs(nb[node][i]);
}

int main()
{
    int x, y, ans = 0, i;
    fin >> n >> m;
    for(i = 0; i < m; i++){
        fin >> x >> y;
        nb[x].push_back(y);
        nb[y].push_back(x);
    }
    for(i = 1; i <= n; i++)
        if(viz[i] == 0){
            dfs(i);
            ans++;
        }
    fout << ans;


    return 0;
}