#include <iostream>
#include <fstream>

using namespace std;

int n,m,x,y,l[200001][1001],k;
bool viz[200001];

void dfs(int i)
{
    if(viz[i]==false)
    {
        viz[i]=true;
        for(int j=1;j<=l[i][0];j++)
        {
            if(viz[l[i][j]]==false)
                dfs(l[i][j]);
        }
    }
}
int main()
{
    int i,j;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    cin>>n>>m;
    for(i=1;i<=m;i++)
    {
        cin>>x;
        cin>>y;
        l[x][0]++;
        l[x][l[x][0]]=y;
        l[y][0]++;
        l[y][l[y][0]]=x;
    }/*
    for(i=1;i<=n;i++)
    {
        for(j=1;j<=l[i][0];j++)
            cout<<l[i][j]<<" ";
        cout<<"\n";
    }*/
    for(i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            dfs(i);
            k++;
        }
    }
    cout<<k<<"\n";
    return 0;
}