#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;
vector <int> graf[100010];
bool viz[100010];

void dfs(int x)
{
    viz[x]=1;
    for(auto i : graf[x])
        if(!viz[i])
            dfs(i);
}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int n,m,a,b,ans=0;
    cin>>n>>m;
    while(m--)
    {
        cin>>a>>b;
        graf[a].push_back(b);
        graf[b].push_back(a);
    }
    for(int i=1;i<=n;i++)
        if(!viz[i])
        {
            dfs(i);
            ans++;
        }
    cout<<ans;
    return 0;
}