#include <stdio.h>
#include <stdlib.h>
 
int n, m, viz[100005], cnt;
 
typedef struct nod
{
    int info;
    nod *urm;
} *tnod;
tnod v[100005];
 
void push(tnod &dest, int val)
{
    tnod p;
    p = new nod;
    p -> info = val;
    p -> urm = dest;
    dest = p;
}
 
void citire()
{int i, x, y;
    
    scanf("%d %d",&n,&m);
    
 
    for (i = 1; i <= m; i++)
    {
        scanf("%d %d",&x,&y);
        push(v[x], y);
        push(v[y], x);
    }
}
 
void DFS(int nod)
{tnod p;
 
    viz[nod] = 1;
    for (p = v[nod]; p != NULL; p = p -> urm) if (!viz[p -> info]) DFS(p -> info);
}  
 
int main()
{int ct;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    citire();
    int i;
    ct = 0;
    for (i=1;i<=n;i++)
    if (!viz[i])
    {
                ++ct;
                DFS(i);}
    printf("%d",ct);
    return 0;
}