#include <bits/stdc++.h>

using namespace std;
const int Nmax=100005;
vector<int>L[Nmax];
int n,m;
bool viz[Nmax];
ifstream fin("dfs.in");
ofstream fout("dfs.out");
void DFS(int varf)
{
    viz[varf]=true;
    for(auto i:L[varf])
        if(!viz[i])
            DFS(i);
}
int main()
{
    int nrc=0;
    fin>>n>>m;
    while(m--)
    {
        int x,y;
        fin>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(!viz[i])
    {
        DFS(i);
        nrc++;
    }
    fout<<nrc<<"\n";
    fin.close();
    fout.close();
    return 0;
}