#include <iostream>
#include <fstream>

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int Start[100005],T[2][400005],n,m,viz[100005],k,contor=0;
void Citire()
{
    int i,j;
    f>>n>>m;
    while (f>>i>>j)
    {
        k++;
        T[0][k]=j;
        T[1][k]=Start[i];
        Start[i]=k;
        k++;
        T[0][k]=i;
        T[1][k]=Start[j];
        Start[j]=k;
    }
}

void dfs(int elem)
{
    int c;
        c=Start[elem];
        viz[elem]=1;
        while(c)
        {
            if(viz[T[0][c]]==0) dfs(T[0][c]);
            c=T[1][c];
        }
}
int main()
{
    Citire();
    for(int i=1;i<=n;i++)
        if(viz[i]==0)
        {
            contor++;
            dfs(i);
        }
    g<<contor;
}