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

using namespace std;



vector<int> a[100002];
bool col[100002];



void backt(int x)
{
    int i,n;
    col[x]=1;
    n=a[x].size();
    for(i=0;i<n;++i)
    if(col[a[x][i]]==0)
    backt(a[x][i]);
}





int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int m,n,i,x,y,nr=0;
    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(col[i]==0)
    {
        ++nr;
        backt(i);
    }
    printf("%d",nr);
}