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

using namespace std;

int n, m, x, y, S;
bool visited[100005];
vector <int> A[100005];

void DFS (int node){
    visited[node] = true;
    int len = A[node].size();
    for(int i = 0; i < len; ++i){
        if(visited[A[node][i]] == false)
            DFS(A[node][i]);
    }

}

int main(){

    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    int n, m, nr = 0;
    scanf("%d%d", &n, &m);

    for(int i = 0; i < m; ++i){
        scanf("%d%d", &x, &y);
        A[x].push_back(y);
        A[y].push_back(x);
    }

    for(int i = 1; i <= n; ++i){
        if(visited[i] == false){
            nr++;
            DFS(i);
        }
    }
    printf("%d", nr);
    return 0;
}