#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
vector<int> v[100100];
int x,y,n,m,ap[100100],nrc;
void DFS(int x)
{
    ap[x]=1;
    for(auto &it:v[x])
        if(!ap[it])
            DFS(it);
}
int main() {
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(!ap[i])
        {
            nrc++;
            DFS(i);
        }
    out<<nrc;
    return 0;
}