#include<cstdio>
#include<vector>
#include<queue>
#define NMAX 100100

using namespace std;

bool used[NMAX];
vector<int> L[NMAX];

void DF(int nod)
{
    vector<int> :: iterator it;
    used[nod] = 1;
    for(it = L[nod].begin() ; it != L[nod].end() ; it++)
        if(!used[*it])
            DF(*it);
}

int main()
{
    int N,M,x,y,i,num=0;

    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);
            L[x].push_back(y);
            L[y].push_back(x);
        }

    for(i=1;i<=N;i++)
        if(!used[i])
        {
            DF(i);
            num++;
        }

    printf("%d",num);
    return 0;
}