#include <fstream>
#include <vector>
#define NMAX 100009
using namespace std;

FILE * fin=fopen("dfs.in", "r");
FILE * fout=fopen("dfs.out", "w");

int n, m, comp;
bool uz[NMAX];
vector <int> L[NMAX];

void dfs (int vf);

int main()
{
    int i, x, y;
    fscanf(fin, "%d %d\n", &n, &m);
    for(i=1; i<=m; ++i)
    {
        fscanf(fin, "%d %d\n", &x, &y);
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for(i=1; i<=n; ++i)
        if(!uz[i])
        {
            ++comp;
            dfs(i);
        }
    fprintf(fout, "\%d\n", comp);
    fclose(fout);
    return 0;
}

void dfs (int vf)
{
    uz[vf]=1;
    int i;
    for(i=0; i<L[vf].size(); ++i)
        if(!uz[L[vf][i]])
            dfs(L[vf][i]);
}