#include <stdio.h>
#include<vector>
using namespace std;
vector<int> a[100001];
bool v[100001];
int n,m;
void cit(){
    freopen("dfs.in","r",stdin);
    int i,j,h;
    scanf("%i%i",&n,&m);
    for(h=1;h<=m;h++){
        scanf("%i%i",&i,&j);
        a[i].push_back(j);
        a[j].push_back(i);
    }
}
void dfs(int k){
    v[k]=1;
    for(vector<int>::iterator it=a[k].begin();it!=a[k].end();it++)
        if(!v[*it])
            dfs(*it);
}
int main(){
    freopen("dfs.out","w",stdout);
    cit();
    int i,nr=0;
    for(i=1;i<=n;i++)
        if(!v[i]){
            nr++;
            dfs(i);
        }
    printf("%i",nr);
    return 0;
}