#include <bits/stdc++.h>

using namespace std;

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

int n, m, x, y;
bool viz[100001];
vector<int>G[100001];

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

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