#include <cstdio>
#include <vector>

using namespace std;

#define maxn 100010

int n,m,viz[maxn];

vector <int> A[maxn];

void Read()
{
    int aux1,aux2;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%i %i",&n,&m);
    for(int i=1;i<=m;i++)
    {
        scanf("%i %i",&aux1,&aux2);
        A[aux1].push_back(aux2);
        A[aux2].push_back(aux1);
    }
}

void DFS(int nod)
{
    int te;
    viz[nod] = 1;
    for(int i=0;i<A[nod].size();i++)
    {
        te = A[nod][i];
        if(viz[te] == 0)
        {
            viz[te] = 1;
            DFS(te);
        }
    }
}

int main()
{
    int k=0;
    Read();
    for(int i=1;i<=n;i++)
    {
        if(viz[i] == 0)
        {
            k++;
            DFS(i);
        }
    }
    printf("%i",k);
    return 0;
}