#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_multiset;
#define ll long long
#define pb push_back
#define all(x) x.begin(), x.end()
const int mod = 1000000007;
const int N = 200005;
ll a[N+2], dp[N+2], cost[N+2];
bool vis[N+2];
struct Dsu{
vector<int> par, rank;
Dsu(int n) : par(n), rank(n){
for(int i = 0; i < n; i++){
par[i] = i;
}
}
int find(int u){
if(u == par[u])return u;
return par[u] = find(par[u]);
}
void merge(int u, int v){
u = find(u), v = find(v);
if(u == v)return;
if(rank[u] < rank[v])swap(u, v);
rank[u] += (rank[u] == rank[v]);
par[v] = u;
}
};
vector<array<ll, 2>> adj[N+2];
vector<ll> order;
void dfs(int n){
vis[n] = 1;
// cout<<n<<' '<<cost[n]<<'\n';
order.pb(n);
for(auto [i, w] : adj[n]){
if(!vis[i]){
cost[i] = cost[n] + w;
dfs(i);
}
}
}
void solve(){
int n;
cin>>n;
vector<array<ll, 3>> v;
for(int i = 0; i < n; i++){
ll u, k;
cin>>u>>k;
--u;
v.pb({k, u, i});
}
sort(all(v), greater<>());
Dsu dsu(n);
ll ans = 0;
for(int i = 0; i < n; i++){
if(dsu.find(v[i][1]) != dsu.find(v[i][2])){
dsu.merge(v[i][1], v[i][2]);
// cout<<"Added edge -> "<<v[i][1]<<' '<<v[i][2]<<'\n'<<"With cost -> "<<v[i][0]<<'\n';
adj[v[i][1]].pb({v[i][2], v[i][0]});
adj[v[i][2]].pb({v[i][1], v[i][0]});
}
}
for(int i = 0; i < n; i++){
if(!vis[i]){
// cout<<i<<'\n';
dfs(i);
array<ll, 2> mx = {0, 0};
for(auto j : order){
if(cost[j] > mx[0]){
mx[0] = cost[j];
mx[1] = j;
}
vis[j] = 0;
cost[j] = 0;
}
order.clear();
// cout<<'\n';
dfs(mx[1]);
mx = {0, 0};
for(auto j : order){
if(cost[j] > mx[0]){
mx[0] = cost[j];
mx[1] = j;
}
}
// cout<<mx[0]<<'\n';
ans += mx[0];
order.clear();
}
}
cout<<ans;
}
int main(){
cin.tie(0)->sync_with_stdio(0);
int tt = 1;
//cin>>tt;
while(tt--){
solve();
cout<<'\n';
}
}
