#include <bits/stdc++.h>
using namespace std;
const int NMAX = 100000;
vector<int>v[NMAX + 5];
bool viz[NMAX + 5];
void dfs(int x){
    viz[x] = 1;
    for (int i = 0; i < v[x].size(); i ++)
        if (viz[v[x][i]] == 0)
            dfs(v[x][i]);
}
int main(){
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    int n, m, a, b, i, ans = 0;
    scanf("%d%d", &n, &m);
    for (i = 1; i <= m; i ++){
        scanf("%d%d", &a, &b);
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for (i = 1; i <= n; i ++){
        if (viz[i] == 0){
            ans ++;
            dfs(i);
        }
    }
    printf("%d\n", ans);
    return 0;
}