#include <cstdio>
#include <vector>
using namespace std;
#define MAX 100001
vector <int> lad[MAX];
vector <bool> viz(MAX);
int n, m, rez;
void dfs(int nod);
int main()
{
    int i, source, dest;
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    scanf("%d%d", &n, &m);
    for(i=1; i<=m; i++){
        scanf("%d%d", &source, &dest);
        lad[source].push_back(dest);
        lad[dest].push_back(source);
    }
    for(i=1; i<=n; i++)
        if(!viz[i]){
            rez++;
            dfs(i);
        }
    printf("%d\n", rez);
    return 0;
}
void dfs(int nod){
    viz[nod] = true;
    for(vector <int>::iterator it=lad[nod].begin(); it<lad[nod].end(); ++it)
        if(!viz[*it])
            dfs(*it);
}