#include <bits/stdc++.h>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, m, viz[100010], a, b, nr;
vector <int> v[100010];
void dfs(int k)
{
    viz[k]=1;
    if(v[k].size())
        for(int i=0; i<=v[k].size()-1; ++i)
            if(viz[v[k][i]]==0)
                dfs(v[k][i]);
}
int main()
{
    fin>>n>>m;
    for(int i=1; i<=m; ++i)
    {
        fin>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(int i=1; i<=n; ++i)
    {
        if(viz[i]==0)
        {
            nr++;
            dfs(i);
        }
    }
    fout<<nr;
    return 0;
}