#include<cstdio>
#include<fstream>
#include<bitset>
#include<vector>
using namespace std;
vector<int>v[100000];
bitset<100000>viz;
int n,m,cont;
void citire(){
    ifstream f("dfs.in");
    f>>n>>m;
    for(int x,y,i=1;i<=m;++i){
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}
void dfs(int x){
    vector<int>:: iterator it;
    viz[x]=1;
            for(it=v[x].begin(); it!=v[x].end(); ++it)
                if(!viz[*it]){
                    dfs(*it);
                }
}
int main(){
    citire();
    for(int i=1;i<=n;++i)
        if(!viz[i]) {
            cont++;
            dfs(i);
        }
    freopen("dfs.out","w",stdout);
        printf("%d",cont);
return 0;
}