#include <algorithm>
#include <iostream>
#include <vector>
#include <queue>
using namespace std;

int N;
vector< vector<int> > sousedi;
vector<int> stupen;
vector<bool> pouzil;

int main() {
    cin >> N;
    sousedi.resize(N);
    stupen.resize(N, 0);
    pouzil.resize(N, false);
    for (int i=0; i<N; ++i) {
        int a, b; cin >> a >> b; a--; b--;
        sousedi[a].push_back(b); ++stupen[a];
        sousedi[b].push_back(a); ++stupen[b];
    }

    queue<int> Q;
    for (int i=0; i<N; ++i) if (stupen[i]==1) Q.push(i);

    int reseni = 0;
    while (!Q.empty()) {
        int kde = Q.front(); Q.pop();
        if (pouzil[kde] || stupen[kde] == 0)
	    continue;   // Tento vrchol jsme použili nebo zablokovali

        int sous = -1;
        for (int a : sousedi[kde]) if (!pouzil[a]) sous=a;

        pouzil[kde] = pouzil[sous] = true;
        ++reseni;
        for (int a : sousedi[kde])
	    if (!pouzil[a]) { --stupen[a]; if (stupen[a]==1) Q.push(a); }
        for (int a : sousedi[sous])
	    if (!pouzil[a]) { --stupen[a]; if (stupen[a]==1) Q.push(a); }
    }

    int na_cyklu = 0;
    for (int i=0; i<N; ++i)
        if (!pouzil[i] && stupen[i]>1) ++na_cyklu;
    reseni += (na_cyklu/2);

    cout << reseni << endl;
}