#include <fstream>
using namespace std;
ifstream in ("dfs.in");
ofstream out ("dfs.out");
int viz[1001], k, j, a[1001][1001], n;
void dfs (int x)
{
    viz[x]=k;
    for(int i=1; i<=n; i++)
    {
        if(a[x][i]==1&&viz[i]==0)
        {
            dfs(i);
        }
    }
}

int main()
{
    int m, b, c;
    in >> n >> m;
    for(j=1; j<=m; j++)
    {
        in >> c >> b;
        a[c][b]=a[b][c]=1;
    }
    for(j=1; j<=n; j++)
    {
        if(viz[j]==0)
        {
            k++;
            dfs(j);
        }
    }
    out << k;
    return 0;
}