#include <stdio.h>
#include <vector>

#define NMAX 100010

using namespace std;

vector<int> G[NMAX];
int X, Y, N, M, C, V[NMAX];

void DFS(int nod)
{
    int nodc, nrnod = G[nod].size();
    V[nod] = 1;

    for(int i = 0; i < nrnod; ++i)
    {
        nodc = G[nod][i];
        if(V[nodc] == 0)
            DFS(nodc);
    }
}

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

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

    for(int nod = 1; nod <= N; ++nod)
        if(V[nod] == 0)
        {
            C++;
            DFS(nod);
        }

    printf("%d", C);

    return 0;
}