#include <bits/stdc++.h>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> v[100002];
vector <int>::iterator it;
bitset <100002> viz;
int n,m,x,y,comp;
void dfs(int k)
{
    viz[k]=1;
    for(it = v[k].begin(); it != v[k].end(); ++ it)
        if(!viz[*it]) dfs(*it);
}
int main()
{
    fin>>n>>m;
    while(m--)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;++i)
        if(!viz[i])
    {
        comp++;
        dfs(i);
    }
    fout<<comp;
    return 0;
}