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

using namespace std;

#define NMAX 100005

vector<int> graph[NMAX];
char viz[NMAX];
int n, m, answer;

void dfs(int node) {
    if(viz[node])
        return ;
    viz[node] = 1;
    for(auto vecin : graph[node]) {
        dfs(vecin);
    }
}

int main() {
    int a, b;
    
    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", &a, &b);
        graph[a].push_back(b);
        graph[b].push_back(a);
    }
    
    for(int i = 1; i <= n; i++) {
        if(!viz[i]) {
            dfs(i);
            answer++;
        }
    }
    
    printf("%d\n", answer);
    
    return 0;
}