#include <bits/stdc++.h>
using namespace std;
ifstream fin ("componenteconexe2.in");
ofstream fout ("componenteconexe2.out");
int n , a[105][105] , nrm , nrnod;
bool viz[105];
void DFS(int nod)
{
    viz[nod] = true;
    nrnod++;
    for(int i = 1 ; i <= n ; i++)
        if(a[nod][i] == 1)
            nrm++;
    for(int i = 1 ; i <= n ; i++)
        if(viz[i] == 0 && a[nod][i] == 1)
            DFS(i);
}
int main()
{
    int  x , y , s = 0;
    fin >> n;
    while(fin >> x >> y)
        a[x][y]  = a[y][x] = 1;
    for(int i = 1 ; i <= n ; i++)
        if(!viz[i])
    {
        nrm = nrnod = 0;
        DFS(i);
        nrm /= 2;
        s += (nrm - nrnod + 1);
    }
    fout << s << "\n";
    fin.close();
    fout.close();
    return 0;
}