#include<fstream>
#include<vector>
using namespace std;
bool luate[100010];
vector<int> muchii[100010];
void dfs(int val)
{
    if(luate[val]) //daca l-am parcurs deja, nu mai are sens sa o mai fac o data
        return;
    else
        luate[val]=!luate[val]; //marchez ca parcurs
    for(unsigned int i=0; i<muchii[val].size(); i++)
     dfs(muchii[val][i]); //parcurg toate muchiile lui!
}
int main()
{
    int n,m,comp=0;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(int i=1; i<=m; i++)
    {
        int x,y;
        scanf("%d%d",&x,&y);
        muchii[x].push_back(y);//fac legaturile intre muchii
        muchii[y].push_back(x);
    }
    for(int i=1; i<=n; ++i)
        if(!luate[i]) //daca nu a fost parcurs pana acum,
        {
            ++comp; //cresc numarul comp. conexe
            dfs(i);
        }
    printf("%d",comp);
}