#include <bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);++i)
#define per(i,a,b) for(int i=(a);i>=(b);--i)
#define pii pair<int,int>
#define fi first
#define se second
#define pb push_back
#define ll long long
using namespace std;
inline ll read(){
    ll x=0,f=1;char ch=getchar();
    while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}
    while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
    return x*f;
}
const int N=1e5+5;
int n,a[N],c[N],mx[N],mx2[N],vis[N];
ll ans;
int main(){
    n=read();
    rep(i,1,n){
        a[i]=read();c[i]=read();
        ans+=c[i];
    }
    rep(i,1,n){
        if(!vis[i]){
            int x=i;
            for(;!vis[x];x=a[x]){
                vis[x]=i;
            }
            if(vis[x]==i){
                int siz=0;
                for(;vis[x]!=-1;x=a[x]){
                    ++siz,vis[x]=-1;
                }
                if(siz==n)return puts("0"),0;
            }
        }
    }
    rep(i,1,n){
        mx[a[i]]=max(mx[a[i]],c[i]);
        if(vis[i]!=-1)mx2[a[i]]=max(mx2[a[i]],c[i]);
    }
    rep(i,1,n)ans-=mx[i];
    rep(i,1,n){
        if(vis[i]==-1){
            int mn=2e9;
            for(int x=i;vis[x]==-1;x=a[x]){
                mn=min(mn,mx[x]-mx2[x]);
                vis[x]=0;
            }
            ans+=mn;
        }
    }
    printf("%lld\n",ans);
    return 0;
}