#include <fstream>
#include <vector>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
int n,m,x,y,r;
vector<vector<int>>a;
bool v[100010];
void dfs(int x)
{
    v[x]=true;
    for(auto q:a[x])
        if(v[q]==false)
            dfs(q);
}
int main()
{
    in>>n>>m;
    a.resize(n+5);
    for(int i=1;i<=m;++i)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(int i=1;i<=n;++i)
    {
        if(v[i]==false)
        {
            ++r;
            dfs(i);
        }
    }
    out<<r;
    return 0;
}