#include <cstdio>
#include <vector>

using namespace std;

vector<int> v[100001];
int viz[100001],n,m;

void Read()
{
    int aux1,aux2;
    FILE *f = fopen("dfs.in","r");
    fscanf(f,"%d %d",&n,&m);
    for(int i=0;i<m;i++)
    {
        fscanf(f,"%d %d",&aux1,&aux2);
        v[aux1].push_back(aux2);
        v[aux2].push_back(aux1);
    }
    fclose(f);
}

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

int main()
{
    FILE *f = fopen("dfs.out","w");
    int rez = 0;
    Read();
    for(int i=1;i<=n;i++)
    {
        if(viz[i] == 0)
        {
            rez++;
            DFS(i);
        }
    }
    fprintf(f,"%d",rez);
    fclose(f);
    return 0;
}