#include <bits/stdc++.h>
#define nmax 100001
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,d[nmax];
bool viz[nmax];
vector<int>L[nmax];
void Read()
{
    int i,x,y;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
}
void Dfs(int varf)
{
    int i,x;
    viz[varf]=true;
    for(i=0;i<L[varf].size();i++)
    {
        x=L[varf][i];
        if(!viz[x])
            Dfs(x);
    }
}
void Solve()
{
    int i,sol=0;
    for(i=1;i<=n;i++)
        if(!viz[i])
    {
        Dfs(i);
        sol++;
    }
    fout<<sol<<"\n";
}
int main()
{
    Read();
    Solve();
    fin.close();
    fout.close();
    return 0;
}