#include <stdio.h>
#include <vector>
using namespace std;
vector<int> noduri[100005]; int n,m; bool v[100005];
void dfs(int nod){
    v[nod]=1;

    for (int i=0; i<noduri[nod].size(); i++)
        if (v[noduri[nod][i]]==0)  dfs(noduri[nod][i]);
}
int main(){
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);

    scanf("%d %d",&n,&m);
    int x,y,nr=0,i;
    for (i=0; i<m; i++)
    {
        scanf("%d %d",&x,&y);
        noduri[x].push_back(y);
        noduri[y].push_back(x);
    }
    for (i=1;i<=n; i++)
        if (v[i]==0){nr++; dfs(i);}
    printf("%d",nr);
}