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

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

vector<int> L[100005];
bool ap[100005];
int n,m;

void dfs(int nod)
{
    ap[nod]=1;
    for(auto it: L[nod])
    {
        if(!ap[it])
            dfs(it);
    }
}

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