#include <bits/stdc++.h>
#define NMax 1000001
using namespace std;

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

int a, b, n, m, con = 0;
bool vis[NMax];
vector<int> v[NMax];

void dfs(int k)
{
    vis[k] = true;
    for (int i = 0; i < v[k].size(); i++)
    {
        int vecin=v[k][i];
        if (!vis[vecin])
            dfs(vecin);
    }
}

int main()
{
    fin>>n>>m;
    for(int i = 1; i <= m; i++)
    {
        fin>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for (int i = 1; i <= n; i++)
    {
        if(!vis[i])
        {
            con++;
            dfs(i);
        }
    }
    fout<<con;
    return 0;
}