#include <cstdio>
#include <cstdlib>
#include <vector>
#include <algorithm>
using namespace std;

#define Nmax 100010
#define pb push_back
#define forit(it, v) for(typeof((v).begin()) it = (v).begin(); it != (v).end(); ++ it)

int N, M, X, Y, Ans;
bool Used[Nmax];
vector<int> G[Nmax];

void DFS(int Node)
{
    Used[Node] = 1;
    forit(it, G[Node])
        if(!Used[*it])
            DFS(*it);
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    int i;
    scanf("%i %i", &N, &M);
    for(i = 1; i <= M; ++ i)
    {
        scanf("%i %i", &X, &Y);
        G[X].pb(Y);
        G[Y].pb(X);
    }
    for(i = 1; i <= N; ++ i)
        if(!Used[i])
        {
            Ans ++;
            DFS(i);
        }
    printf("%i\n", Ans);
    return 0;
}