#include <fstream>
#include<vector>
#define pb push_back
using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
vector<int>v[100001];
bool f[100001];
int c;
void dfs(int nod){
    f[nod]=1;
    for(int i=0;i<v[nod].size();i++){
        if(f[v[nod][i]]==0)
            dfs(v[nod][i]);
    }
}
int main()
{
    int n,m,i,j;
    cin>>n>>m;
    for(i=1;i<=m;++i){
        int a,b;
        cin>>a>>b;
        v[a].pb(b);
        v[b].pb(a);
    }
    for(i=1;i<=n;i++)
        if(f[i]==0)
            c++,dfs(i);
    cout<<c;
    return 0;
}