#include<bits/stdc++.h>
#define int long long
using namespace std;
auto IN = freopen("religion.in", "r", stdin);
auto OUT = freopen("religion.out", "w", stdout);
auto mread = [](){int x;scanf("%lld", &x);return x;};
const int N = 5e4 + 5;
int n = mread(), m = mread(), fa[N];
int findfa(int x){
    if(x == fa[x]){
        return x;
    }
    return fa[x] = findfa(fa[x]);
}
signed main(){
    for(int i = 1; i <= n; i ++){
        fa[i] = i;
    }
    for(int i = 1, x, y; i <= m; i ++){
        x = mread(), y = mread();
        fa[findfa(x)] = findfa(y);
    }
    set<int> s;
    for(int i = 1; i <= n; i ++){
        s.insert(findfa(i));
    }
    printf("%lld", (int)s.size());
    return 0;
}