#include <cstdio>
#include <stdio.h>
#include <stdbool.h>
#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
#include <numeric>
#include <cassert>
#include <random>
#include <chrono>
#include <fstream>
using namespace std;
#define int long long
#define mp make_pair
#define pii pair<int, int>
#define fi first
#define se second
#define pb push_back
vector<bool> visited;
vector<vector<int> > graph;
void dfs(int node){
visited[node]=1;
for (auto num:graph[node])if (!visited[num])dfs(num);
}
int32_t main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, t=0, ans=0;
cin>>n;
vector<int> nx(n+1), mx(n+1, 0), mx2(n+1, 0), id(n+1, 0), vect(n+1);
graph.resize(n+1);
visited.resize(n+1);
for (int i=1; i<=n; ++i){
cin>>nx[i]>>vect[i];
t+=vect[i];
graph[nx[i]].pb(i);
}
for (int i=1; i<=n; ++i)for (auto num:graph[i]){
if (vect[num]>mx[i])mx2[i]=mx[i], mx[i]=vect[num], id[i]=num;
else if (vect[num]>mx2[i])mx2[i]=vect[num];
}
for (int i=1; i<=n; ++i)ans+=mx[i];
vector<bool> done(n+1, 0);
for (int i=1; i<=n; ++i)if (!visited[i]){
deque<int> ord;
int mn=LLONG_MAX/2, c=i;
while (!done[c])done[c]=1, ord.pb(c), c=nx[c];
while (ord[0]!=c)ord.pop_front();
if (ord.size()==n){
cout<<0;
return 0;
}
for (auto c:ord)visited[c]=1;
for (int i=0; i<ord.size(); ++i)dfs(ord[i]);
bool got=0;
for (int i=0; i<ord.size(); ++i)if (id[ord[i]]!=ord[(i-1+ord.size())%ord.size()])got=1;
if (got)continue;
for (int i=0; i<ord.size(); ++i)mn=min(mn, mx[ord[i]]-mx2[ord[i]]);
ans-=mn;
}
cout<<t-ans;
}
