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

using namespace std;

vector <int> graph[100005];
int visited[100005], n, x, y, nr, i, m;

void dfs ( int node ) {
    visited[node] = 1;
    for ( auto i: graph[node] ) {
        if ( visited[i] == 0 ) {
            dfs ( i );
        }
    }
}

int main() 
{
    ifstream cin ("dfs.in");
    ofstream cout ("dfs.out");
    
    cin >> n >> m;

    for ( i = 1; i <= m; i++ ) {
        cin >> x >> y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    for ( i = 1; i <= n; i++ ) {
        if ( visited[i] == 0 ) {
            dfs ( i );
            nr++;
        }
    }

    cout << nr;
    
    return 0;
}