#include <iostream>
#include <fstream>
#include <vector>
#include <bitset>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
vector < int > arbore[100005];
bitset < 100005 > trecut;
int n,m,k,x,y;
void dfs(int sursa){
    trecut[sursa]=true;
    vector < int > ::iterator it;
    for(it=arbore[sursa].begin();it!=arbore[sursa].end();++it){
        int vecin=*it;
        if(trecut[vecin]==0) dfs(vecin);
    }


    }

int main()
{
    in>>n>>m;
    for(int i=1;i<=m;++i){
        in>>x>>y;
        arbore[x].push_back(y);
        arbore[y].push_back(x);
    }
    for(int i=1;i<=n;++i){
        if(trecut[i]==0) {dfs(i);k++;}
    }
    out<<k;
    return 0;
}