#include <fstream>
#include <vector>

using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");

const int N=100010;
vector<int>a[N];
int n,m;
bool viz[N];

void read()
{
    int x,y;
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}

void dfs(int x)
{
    viz[x]=1;
    for(unsigned int i=0;i<a[x].size();i++)
        if(!viz[ a[x][i] ])
            dfs(a[x][i]);
}
int main()
{
    int c=0,i;
    read();
    for(i=1;i<=n;i++)
        if(!viz[i])
        {
            dfs(i);
            c++;
        }
    out<<c<<"\n";
    return 0;
}