#include <fstream>
#include <vector>
using namespace std;

typedef vector<int> VI;

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

VI g[100001];
int v[100001];
int n, m, p;

void Read();
void DFS(int str);

int main()
{
    Read();
    for (int i = 1; i <= n; ++i )
        if ( v[i] == 0)
        {
            DFS(i);
            p++;
        }
        fout << p;
}

void Read()
{
    fin >> n >> m;
    int a, b;
    while ( m)
    {
        fin >> a >> b;
        g[a].push_back(b);
        g[b].push_back(a);
        m--;
    }

}

void DFS(int str)
{
    v[str] = 1;
    for ( VI::iterator it = g[str].begin(); it != g[str].end(); ++it )
        if ( v[*it] == 0 )
            DFS(*it);

}