#include <fstream>
#include <vector>

std::ifstream f("dfs.in");
std::ofstream g("dfs.out");

const int NMAX =  100'005;
int n,m,componente,x,y;
bool visited[NMAX];

std::vector<int>L[NMAX];

void dfs(int nod){
    
    visited[nod] = true;
    
    for(int vecin : L[nod])
        if(!visited[vecin])
            dfs(vecin);
}

int main(){
    
    f >> n >> m;
    
    for(int i = 1;i <= m;++i){
        
        f >> x >> y;
        
        L[x].push_back(y);
        L[y].push_back(x);
    }
    
    for(int nod = 1;nod <= n;++nod){
        
        if(!visited[nod]){
            dfs(nod);
            componente++;
        }
    }
    
    g << componente;
    
    
    return 0;
}