#include <stdio.h>
#include <vector>
#define NMAX 100002
using namespace std;

int N, M;

vector <int> vf[NMAX];
bool vizitat[NMAX];

void DFS(int x){
    vizitat[x] = 1;
    for(int i = 0 ; i < vf[x].size(); i++){
        if(vizitat[vf[x][i]] == 0){
            DFS(vf[x][i]);
        }
    }
}

int main(){

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

    int i, x, y, cnt;
    scanf("%d%d", &N, &M);

    for(i = 1; i <= M; i++){
        scanf("%d%d", &x, &y);
        vf[x].push_back(y);
        vf[y].push_back(x);
    }

    cnt = 0;
    for(i = 1; i <= N; i++){
        if(vizitat[i] == 0){
            cnt++; DFS(i);
        }
    }
    printf("%d", cnt);
}