#include <iostream>
#include <fstream>
#include <vector>

using namespace std;
#define MaxN 100002
vector<int> graph[MaxN];
int marked[MaxN];

void add(int a, int b)
{
    graph[a].push_back(b);
    graph[b].push_back(a);
}

void dfs(int nod)
{
    marked[nod]=1;
    for(int i: graph[nod])
    {
        if(marked[i]==0) dfs(i);
    }
}
int main()
{
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    int n, m, i, j, a, b, cnt=0;
    in>>n>>m;
    for(i=0; i<m; i++)
    {
        in>>a>>b;
        add(a, b);
    }
    for(i=1; i<=n; i++)
    {
        if(marked[i]==0) { dfs(i); cnt++;}
    }
    out<<cnt;
    return 0;
}