#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
const int N = 100105;
vector <int> v[N];
bool vf[N];
void DFS(int nod)
{
    vf[nod] = 1;
    for(auto it : v[nod]){
        if(vf[it] == 0){
            DFS(it);
        }
    }
}

int main()
{
    int n, m, i, x, y;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d%d", &n, &m);
    for(i = 1;i <= m; ++i){
        scanf("%d%d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int afis = 0;
    for(i = 1;i <= n; ++i){
        if(vf[i] == 0){
            DFS(i);
            ++afis;
        }
    }
    printf("%d\n",afis);
    return 0;
}