#include <fstream>
#include <vector>
#define K 100001
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,i,x,y,sol,f[K];
vector <int> v[K];
void dfs(int x){
    f[x]=1;
    for(int i=0;i<v[x].size();i++)
        if(!f[v[x][i]])
            dfs(v[x][i]);
}
int main(){
    fin>>n>>m;
    for(;m--;){
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(!f[i]){
            dfs(i);sol++;}
    fout<<sol;
    return 0;
}