#include <stdio.h>
#include <vector>
#define NMax 100002
using namespace std;
vector <int> G[NMax];
int n,m,nr=0;
int vizitat[NMax];
void read()
{
    int i,x,y;
    freopen("dfs.in","r",stdin);
    scanf("%d%d",&n,&m);
    for(i=1;i<=m;i++)
    {
        scanf("%d%d",&x,&y);

         G[x].push_back(y);
         G[y].push_back(x);
    }vector<int>::iterator it;
    fclose(stdin);
}
void dfs(int s)
{
    vector<int>::iterator it;
    vizitat[s]=1;
    for(it=G[s].begin();it!=G[s].end();it++)
    {
        if(!vizitat[*it]) dfs(*it);
    }

}
int main()
{
    int i;
    read();
    for(i=1;i<=n;i++)
    {
        if(!vizitat[i]) {nr++;dfs(i);}
    }
    freopen("dfs.out","w",stdout);
    printf("%d",nr);
    fclose(stdout);
    return 0;


}