#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

bool v[100005];
int n, m, a, b;
vector<vector<int>> G;

void dfs(int x)
{
    v[x] = 1;
    for ( int a : G[x] )
        if ( !v[a] )
            dfs(a);
}

int main()
{
    fin >> n >> m;
    G.resize(n + 1);

    for ( int i = 1; i <= m; i++ )
    {
        fin >> a >> b;
        G[a].push_back(b);
        G[b].push_back(a);
    }

    int cnt = 0;
    for ( int i = 1; i <= n; i++ )
        if ( !v[i] )
        {
            cnt++;
            dfs(i);
        }
    fout << cnt;
}