#include <cstdio>
#include <vector>

#define NMAX 100007

using namespace std;

vector <int> v[NMAX];
int Viz[NMAX];
int n , m , x , y , nr;

void dfs(int Nod){
    Viz[Nod] = 1;
    for(vector<int> :: iterator i = v[Nod].begin(); i != v[Nod].end(); ++i)
        if(Viz[*i] == 0)
            dfs(*i);
}

int main(){
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    scanf("%d %d" , &n , &m);
    for( ; m > 0 ; --m){
        scanf("%d %d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i  =1; i <= n; ++i)
        if(Viz[i] == 0){
            ++nr;
            dfs(i);
        }
    printf("%d", nr);
    return 0;
}