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