#include <bits/stdc++.h>
#define nMax 100005

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

int n, m, x, y, conex;
vector<int> G[nMax];
bitset<nMax> viz;

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

int main()
{
    fin >> n >> m;
    while(m--)
    {
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
        if(!viz[i])
        {
            conex++;
            dfs(i);
        }
    fout << conex;
    return 0;
}