#include <bits/stdc++.h>
#define longc 100005

using namespace std;
int n,m,viz[longc],nr;
vector<int > G[longc];
void read() {

    scanf("%d%d",&n,&m);
    int x,y;
    for (int i=1; i<=m; ++i) {
        scanf("%d%d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }

}

void par_dfs(int pz) {
    viz[pz]=1;
    for (vector <int > :: iterator it=G[pz].begin() ; it!=G[pz].end() ; ++it) {
        if (!viz[*it])
            par_dfs(*it);
    }
}

int main() {
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    read();
    for (int i=1; i<=n; ++i)
            if (!viz[i])
            {
                par_dfs(i);
                nr++;
            }
    printf("%d",nr);

    return 0;
}