#include <iostream>
#include <fstream>
#include <vector>
#define Nmax 100002

using namespace std;

FILE *f=fopen("dfs.in","rt");
ofstream g("dfs.out");

vector<int> G[Nmax];

int i,n,m,x,y,nr;
bool used[Nmax];

void read(){
    fscanf(f,"%d%d",&n,&m);
    for(i=0;i<m;++i){
        fscanf(f,"%d%d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void dfs(int x){
    used[x]=true;
    for(int i=0;i<G[x].size();++i){
        int vec=G[x][i];
        if(!used[vec])
            dfs(vec);
    }
}

int main()
{
    read();
    for(i=1;i<=n;++i)
        if(!used[i])
            dfs(i),++nr;
    g << nr;
    return 0;
}