#include <bits/stdc++.h>
#define MOD 1999999973
using namespace std;

int n, m, cc, fv[100005], a, b;

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

vector < int > G[100005];

void dfs ( int nod )
{
    fv[nod] = 1;

    for ( auto i : G[nod] )
    {
        if ( fv[i] == 0 )
        {
            dfs(i);
        }
    }

}

int main ()
{
    f>>n>>m;

    for ( int i = 1; i <= m ; i++ )
    {
        f>>a>>b;
        G[a].push_back(b);
        G[b].push_back(a);
    }

    for (int i = 1; i <= n; i++ )
    {
        if ( fv[i] == 0 )
        {
            cc++;
            dfs(i);
        }
    }

    g<<cc;

}