#include <fstream>
#define NMAX 100001
using namespace std;
int freq[NMAX]={0};

void DFS(int *a[],int n,int current){
    freq[current] = 1;
    for(int i=1;i<=n;i++)
        if(a[current][i] && freq[i])
            DFS(a,n,i);
}

int main()
{
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    int n,m,m1,m2,a[NMAX][NMAX];
    f >> n >> m;
    for(int i=0;i<m;i++){
        f >> m1 >> m2;
        a[m1][m2] = a[m2][m1] = 1;
    }
    int c=0;
    for(int i=1;i<=n;i++){
        c++;
        if(!freq[i])    DFS(a,n,i);
    }
    g << c;
    return 0;
}