#include <fstream>
#include <vector>

#define MAX 100001

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

int vizitat[MAX];
int sol;
int n, m, i, j, x, y;
vector <int> v[MAX];

inline void dfs (int x)
{
    vizitat[x] = 1;
    for ( int i = 0; i < v[x].size(); i ++ )
    {
        if ( !vizitat[ v[x][i] ] )
            dfs ( v[x][i] );
    }
}

inline void read ()
{
    f >> n >> m;
    for ( i = 1; i <= m; i ++ )
    {
        f >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}

inline void solve ()
{
    for ( i = 1; i <= n; i ++ )
        if ( !vizitat[i] )
        {
            sol ++;
            dfs(i);
        }
}

inline void write ()
{
    g << sol << "\n";
}

int main()
{
    read();
    solve();
    write();
    return 0;
}