#include <cstdio>
#include <vector>
using namespace std;
#define MAX 100001
vector <int> lista[MAX];
int n, m, nc;
bool v[MAX];
void dfs(int nod);
int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    int i, a, b;
    scanf("%d%d", &n, &m);
    for(i=1; i<=m; i++){
        scanf("%d%d", &a, &b);
        lista[a].push_back(b);
        lista[b].push_back(a);
    }
    for(i=1; i<=n; i++)
        if(!v[i]){
            nc++;
            dfs(i);
        }
    printf("%d\n", nc);
    return 0;
}
void dfs(int nod){
    v[nod] = true;
    for(int i=0; i<lista[nod].size(); i++)
        if(!v[lista[nod][i]])
            dfs(lista[nod][i]);
}