#include <iostream>
#include <fstream>
using namespace std;

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


#define cin fin
#define cout fout

int k,viz[100001],a[100001][100001],n,x,y,m;

void dfs(int nod)
{
    viz[nod]=k;
    for(int i=1; i<=n; i++)
        if(a[nod][i]==1&&viz[i]==0)
            dfs(i);
}


int main()
{
    cin>>n>>m;
    for(int i=1;i<=m;i++)
        {   cin>>x>>y;
            a[x][y]=a[y][x]=1;
        }
    for(int i=1; i<=n; i++)
        if(viz[i]==0)
        {
            k++;
            dfs(i);
        }
    cout<<k<<"\n";
}