#include <cstdio>
#include <vector>
using namespace std;
int N,M;
vector<int> V[100005];
int us[100005];
int SOL=0;
void D(int i){
    us[i]=1;
    for(  vector<int>::iterator it=V[i].begin();it!=V[i].end(); ++it)
        if(  ! us[*it] ) D(*it);
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d%d",&N,&M);
    int x,y;
    while( M-- ){
        scanf("%d%d",&x,&y);
        V[x].push_back(y);
        V[y].push_back(x);}
    for(register int i=1;i<=N;++i )
        if(  !us[i] )
            ++SOL,D(i);
    printf("%d",SOL);
    return 0;
}