#include <iostream>
#include <stdio.h>
#include <vector>

using namespace std;

int n, m, x, y, vizitat[100005], cnt;
vector<int> arr[100005];

void citire(){
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    scanf("%d %d", &n, &m);
    for(int i = 1; i <= m; i++){
        scanf("%d %d", &x, &y);
        arr[x].push_back(y);
        arr[y].push_back(x);
    }
}
void DFS(int val){
    vizitat[val] = 1;
    for(vector<int>::iterator it = arr[val].begin(); it != arr[val].end(); ++it)
        if(!vizitat[*it]){
            DFS(*it);
        }
}

int main() {
    citire();
    for(int i = 1; i <= n; i++)
    if(!vizitat[i]) {
        cnt++;
        DFS(i);
    }
    printf("%d", cnt);
    return 0;
}