#include <cstdio>
#include <vector>

#define DIM 100010

using namespace std;

vector<int> L[DIM];

FILE *fin = fopen("dfs.in","r");
FILE *fout = fopen("dfs.out","w");

int n,m,x,y,i,cc;
int v[DIM];


void dfs(int nod) {
    v[nod] = 1;
    for (int i=0;i<L[nod].size();i++)
        if (v[ L[nod][i]  ] == 0)
            dfs( L[nod][i] );

}

int main() {
    fscanf(fin,"%d %d",&n,&m);
    for (i=1;i<=m;i++) {
        fscanf(fin,"%d %d",&x,&y);
        L[x].push_back(y);
        L[y].push_back(x);
    }

    for (i=1;i<=n;i++)
        if (v[i] == 0) {
            cc++;
            dfs(i);
        }
    fprintf(fout, "%d", cc);
    return 0;
}