#include<cstdio>
#include<vector>
using namespace std;
const int NMAX=100000;
vector<int>G[NMAX+5];
int viz[NMAX+5];
void dfs(int u, int cc)
{
    int v;
    viz[u]=cc;
    for(int j=0;j<G[u].size();j++)
    {
        v=G[u][j];
        if(!viz[v]) dfs(v,cc);
    }
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int n,m,u,v,cc=0,i;
    scanf("%d%d",&n,&m);
    for(i=1;i<=m;i++)
    {
        scanf("%d%d",&u,&v);
        G[u].push_back(v);
        G[v].push_back(u);
    }
    for(i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            cc++;
            dfs(i,cc);
        }
    }
    printf("%d",cc);
    return 0;
}