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

const int NMAX = 100010;

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

void DFS(int Node)
{
    Used[Node] = 1;
    for(vector<int> :: iterator it = G[Node].begin(); it != G[Node].end(); ++ it)
        if(!Used[*it])
            DFS(*it);
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    scanf("%i %i", &N, &M);
    for(int i = 1; i <= M; ++ i)
    {
        scanf("%i %i", &X, &Y);
        G[X].push_back(Y);
        G[Y].push_back(X);
    }

    for(int i = 1; i <= N; ++ i)
        if(!Used[i])
            Ans ++, DFS(i);

    printf("%i\n", Ans);
}