#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
int ans=0;
vector<int> vect, mx;
vector<bool> visited;
vector<vector<int> > graph;
void dfs(int node){
int sum=0;
visited[node]=1;
for (auto num:graph[node])if (!visited[num])dfs(num), sum+=vect[num], mx[node]=max(mx[node], vect[num]);
ans+=sum-mx[node];
}
int32_t main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, del;
cin>>n;
vector<int> nx(n+1);
mx.resize(n+1, 0);
graph.resize(n+1);
vect.resize(n+1);
visited.resize(n+1);
for (int i=1; i<=n; ++i){
cin>>nx[i]>>vect[i];
graph[nx[i]].pb(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();
for (auto c:ord)visited[c]=1;
for (int i=0; i<ord.size(); ++i)dfs(ord[i]), ans+=mx[ord[i]], mn=min({mn, vect[ord[i]], vect[ord[(i+1+ord.size())%ord.size()]]-mx[ord[i]]});
ans+=mn;
del=mn;
}
if (ans==del)cout<<0;
else cout<<ans;
}
