#include <fstream>
#include <bitset>
#include <vector>
using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
const int lim=1e5+5;
vector<int> vec[lim];
bitset<lim> ok;
void dfs(int node)
{
    ok[node]=true;
    for(auto x:vec[node])
    if(!ok[x]) dfs(x);
}
int main()
{
    int n,m,x,y,answer=0;
    cin>>n>>m;
    for(int i=1;i<=m;++i)
    {
        cin>>x>>y;
        vec[x].push_back(y);
        vec[y].push_back(x);
    }
    for(int i=1;i<=n;++i)
    if(!ok[i]) ++answer,dfs(i);
    cout<<answer;
    return 0;
}