#include <bits/stdc++.h>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");

int m,n,i,nr,viz[100002];
vector<int>lista[100002];
queue<int>q;

void citire()
{
    int x,y;
    in>>m>>n;
    for(i=1;i<=n;i++)
    {
        in>>x>>y;
        lista[x].push_back(y);
        lista[y].push_back(x);
    }
}
void dfs(int node)
{
    q.push(node);
    viz[node]=1;
    for(auto x:lista[node])
    {
        if(viz[x]!=1)
            dfs(x);
    }
}
int main()
{
    citire();
    for(i=1;i<=m;i++)
    {
        if(viz[i]==0)
        {
            dfs(i);
            nr++;
        }
    }
    out<<nr;
    return 0;
}