#include<bits/stdc++.h>
#define all(s) s.begin(),s.end()
#define F first
#define S second
using namespace std;
typedef int ll;
ll n,x,y,o,sz[2009],f[2009],lg[4009],ans=1e9;
vector<vector<ll> >v;
pair<ll,ll>p[13][4009];
void dfs(ll d,ll pp,ll h)
{
p[0][o]= {h,d};
f[d]=o++;
sz[d]=1;
for(auto&z:v[d])
if(z!=pp)
{
dfs(z,d,h+1);
p[0][o++]= {h,d};
sz[d]+=sz[z];
}
}
ll lca(ll i,ll j)
{
i=f[i],j=f[j];
if(i>j)
swap(i,j);
ll k=lg[j-i+1];
return min(p[k][i],p[k][j-(1<<k)+1]).S;
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0),cout.tie(0);
cin>>n;
v.resize(n+1);
for(ll i=1; i<n; i++)
{
cin>>x>>y;
v[x].push_back(y);
v[y].push_back(x);
}
dfs(1,0,0);
for(ll i=2; i<=o; i++)
lg[i]=lg[i>>1]+1;
for(ll j=1; j<13; j++)
for(ll i=0; i+(1<<j)<=o; i++)
p[j][i]=min(p[j-1][i],p[j-1][i+(1<<(j-1))]);
for(ll i=1; i<n; i++)
for(ll j=i+1; j<=n; j++)
{
x=lca(i,j);
if(x!=i&&x!=j)
{
ll a=max({sz[i],sz[j],n-sz[i]-sz[j]});
ll b=min({sz[i],sz[j],n-sz[i]-sz[j]});
ans=min(ans,a-b);
}
else
{
if(x==i)
y=j;
else
y=i;
ll a=max({sz[y],sz[x]-sz[y],n-sz[x]});
ll b=min({sz[y],sz[x]-sz[y],n-sz[x]});
ans=min(ans,a-b);
}
}
cout<<ans;
return 0;
}
