#include <cstdio>
#include <vector>
using namespace std;
vector<int>g[100005];
int n,sel[100005],m;
void dfs(int x){
int i;
sel[x]=true;
for(i=0;i<g[x].size();++i)
    if(!sel[g[x][i]])
        dfs(g[x][i]);
}
int i,x,y,nc;
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d %d",&n,&m);
    for(i=1;i<=m;++i){
        scanf("%d %d",&x,&y);
        g[x].push_back(y);
        g[y].push_back(x);
    }
    nc=0;
    for(i=1;i<=n;i++)
    if(!sel[i]){
        ++nc;
        dfs(i);
    }
    printf("%d",nc);


    return 0;
}