#include <bits/stdc++.h>

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

const int N = 100010;

int n, m, c;

vector<int> v[N];

bitset<N> viz;

void dfs(int);

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

    for( ; m ; m--)
    {
        int x, y;
        f >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for(int i = 1; i <= n; i++)
        if( !viz[i] )
        {
            c++;
            dfs(i);
        }
    g << c;
    return 0;
}

void dfs(int nod)
{
    viz[nod] = 1;
    for(auto vec : v[nod])
        if( !viz[vec] )
            dfs(vec);
}