#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
using namespace __gnu_pbds;
using namespace std;
#define pb push_back
#define st first
#define nd second
typedef long long ll;
typedef long double ld;
const ll I = 1000LL * 1000LL * 1000LL * 1000LL * 1000LL * 1000LL;
const ll M = 1000LL * 1000LL * 1000LL + 7LL;
const int N = 1<<17;
bool czd[N];
ll cst[N], dp[N];
vector<int> ed[N];
int il[N], poi[N];

int LiczD(int n)
{
    int v, cnt = 0;
    queue<int> q;
    for(int i = 1; i <= n; ++i)
        if(il[i] == 0) q.push(i);

    while(q.size() > 0)
    {
        ++cnt;
        v = q.front(); q.pop(); 
        czd[v] = true;
        ll ma = 0;
        for(int i = 0; i < (int)ed[v].size(); ++i)
            {dp[v] += dp[ed[v][i]] + cst[ed[v][i]]; ma = max(ma, cst[ed[v][i]]);}
        dp[v] -= ma;
        --il[poi[v]];
        if(il[poi[v]] == 0)
            q.push(poi[v]);
    }
    return cnt;
}

ll LiczC(int v)
{
    ll ans = 0LL, ma = -I;
    int x = poi[v];
    vector<int> ver;
    ver.pb(v);
    while(x != v)
    {
        ver.pb(x);
        x = poi[x];
    }
    for(int i = 0; i < (int)ver.size(); ++i)
    {
        int pr; 
        if(i > 0) pr = ver[i - 1];
        else pr = ver.back();
        v = ver[i]; 
        ll cur = 0LL;
        for(int j = 0; j < (int)ed[v].size(); ++j)
            if(czd[ed[v][j]])
                {ans += dp[ed[v][j]] + cst[ed[v][j]]; cur = max(cur, cst[ed[v][j]]);}


        cur -= cst[pr];
        ma = max(ma, cur);
        //cout << "cycle: " << v << " " << cur << " " << ma << " " << ans << "\n";
    }
    for(int i = 0; i < (int)ver.size(); ++i)
        czd[ver[i]] = true;

    ans -= ma;
    return ans;
}

void Solve()
{
    int n, xd;
    ll ans = 0LL;
    cin >> n;
    for(int i = 1; i <= n; ++i)
    {
        cin >> poi[i] >> cst[i];
        ed[poi[i]].pb(i); ++il[poi[i]];
    }
    xd = LiczD(n);
    for(int i = 1; i <= n; ++i)
        if(!czd[i])
        {
            ++xd;
            ans += LiczC(i);
        }
    
    if(xd == 1)
        cout << 0 << "\n";
    else
        cout << ans << "\n";
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    //int t; cin >> t;
    //while(t--)
        Solve();

    return 0;
}