#include <cstdio>
#include <vector>

#define NMAX 100001
#define FILEIN "dfs.in"
#define FILEOUT "dfs.out"

using namespace std;

vector<int> A[NMAX];
int sol;
int viz[NMAX];
int n,m,i,j,x,y;

void dfs(int node)
{
    int k;
    viz[node] = 1;
    for ( k = 0 ; k < A[node].size(); k++)
    {
        if(!viz[A[node][k]])
            dfs(A[node][k]);
    }
}

int main()
{
    freopen(FILEIN,"r",stdin);
    freopen(FILEOUT,"w",stdout);
    scanf("%d %d", &n, &m);
    for ( i = 1; i <= m; i++ )
    {
        scanf("%d %d", &x, &y);
        A[x].push_back(y);
        A[y].push_back(x);
    }
    for ( i = 1; i <= n; i++)
    {
        if ( !viz[i] )
        {
            sol++;
            dfs(i);
        }
    }
    printf("%d\n", sol);
    return 0;
}