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

using namespace std;

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

const int MAX_N = 1e5;

vector <int> g[MAX_N + 1];
bool vizitat[MAX_N + 1];

void dfs( int u ) {
    
    vizitat[u] = 1;
    
    for ( int i = 0; i < g[u].size(); i++ )
        if ( vizitat[g[u][i]] == 0 )
            dfs ( g[u][i] );
}

int main() {
    
    int n, m, i, cnt = 0;
    
    fin >> n >> m;
    
    for ( i = 0; i < m; i++ ) {
        
        int a, b;
        fin >> a >> b;
        
        g[a].push_back(b);
        g[b].push_back(a);
    }
    
    for ( i = 1; i <= n; i++ )
        if ( vizitat[i] == 0 ) {
            dfs( i );
            cnt++;
        }

    fout << cnt;
    
    return 0;
}