#include <bits/stdc++.h>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
#define cin fin
#define cout fout
long long n,m,a[10001][10001],p,viz[100001];
void citire(){
    cin>>n>>m;
    int x,y;
    for(int i=1;i<=m;i++){
        cin>>x>>y;
        a[x][y]=a[y][x]=1;
    }
}
void dfs(int x){
    viz[x]=1;
    for(int i=1;i<=n;i++){
            if(a[x][i]==1&&viz[i]==0){
                dfs(i);
            }
        }
}

int main()
{
    citire();
    int k=0;
    for(int i=1;i<=n;i++){
        if(!viz[i]){
            k++;
            dfs(i);
        }
    }
    cout<<k;
    return 0;
}