#include <fstream>
#include <vector>

using namespace std;

bool viz[100001];
vector<int>v[100001];

void ff( int nod ) {
    int i;
    viz[nod] = 1;
    for( i = 0; i < v[nod].size(); i++ )
        if( viz[v[nod][i]] == 0 )
            ff( v[nod][i] );
    return;
}

int main() {
    ifstream cin("dfs.in");
    ofstream cout("dfs.out");
    int n, m, i, a, b, k;
    cin>>n;
    cin>>m;
    for( i = 1; i <= m; i++ ) {
        cin>>a>>b;
        v[a].push_back( b );
        v[b].push_back( a );
    }
    k = 0;
    for( i = 1; i <= n; i++ ) {
        if( viz[i] == 0 ) {
            ff( i );
            k++;
        }
    }
    cout<<k;
    return 0;
}