#include <bits/stdc++.h>
using namespace std;
ifstream in ("dfs.in");
ofstream out ("dfs.out");
vector<int> l[100001];
bool v[100001];
void dfs(int u)
{
    v[u]=1;
    int i;
    for (i=0; i<l[u].size(); i++)
        if (v[l[u][i]]==0)
            dfs(l[u][i]);
}
int main()
{
    int n,m,i,a,b,ctr=0;
    in>>n>>m;
    for (i=1; i<=m; i++)
    {
        in>>a>>b;
        l[a].push_back(b);
        l[b].push_back(a);
    }
    for (i=1; i<=n; i++)
    {
        if(v[i]==0)
        {
            dfs(i);
            ctr++;
        }
    }
    out<<ctr;
    return 0;
}