#include <bits/stdc++.h>

using namespace std;

#define     mp              make_pair
#define     fs              first
#define     sc              second
#define     pob             pop_back
#define     pub             push_back
#define     eps             1E-7
#define     sz(a)           a.size()
#define     count_one       __builtin_popcount;
#define     count_onell     __builtin_popcountll;
#define     fastIO          ios_base::sync_with_stdio(false)
#define     PI              (acos(-1.0))
#define     linf            (1LL<<62)//>4e18
#define     inf             (0x7f7f7f7f)//>2e9

#define DEBUG 1
#ifdef DEBUG
#define D(x) x
#else
#define D(x)
#endif

#define MAXN 100000
#define INDEX 1
FILE *in = fopen("dfs.in", "r");
FILE *out = fopen("dfs.out", "w");

int n, m;
int compConexe = 0;
vector<int> vec[MAXN + INDEX];
bitset<MAXN> viz;

void dfs(int nod) {
    for(auto it = vec[nod].begin(); it != vec[nod].end(); it++) {
        if(!viz[*it]) {
            viz[*it] = true;
            dfs(*it);
        }
    }
}

int main()
{
    int x, y;

    fscanf(in, "%d%d", &n, &m);
    while(m--) {
        fscanf(in, "%d%d", &x, &y);
        vec[x].pub(y);
        vec[y].pub(x);
    }

    for(int i = 1; i <= n; ++i) {
        if(!viz[i]) {
            compConexe++;
            viz[i] = true;
            dfs(i);
        }
    }

    fprintf(out, "%d\n", compConexe);
    return 0;
}