#include <cstdio>
#include <vector>

using namespace std;

vector<int> a[100001];
int n, m, i, use[100001];

void dfs(int nod ){
    vector<int>::iterator it;
    use[nod]=1;
    for (it=a[nod].begin();it<a[nod].end();++it){
        if (use[*it]==0) dfs(*it);
    }
}
int main(){
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d %d",&n, &m);
    for (i=1; i<=m; ++i){
        int x,y;
        scanf("%d %d", &x, &y);
        a[x].push_back(y);
        a[y].push_back(x);
    }
    int nrc=0;
    for (i=1; i<=n; ++i){
        if (use[i]==0){
            dfs(i);
            ++nrc;
        }
    }
    printf("%d", nrc);
    return 0;
}