#include<bits/stdc++.h>
#define int long long
#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 fi first
#define se second
#define eb emplace_back
#define popc __builtin_popcount
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<pii> vp;
typedef unsigned long long ull;
typedef long double ld;

int read() {
	int x=0,w=1; char c=getchar(); 
	while(!isdigit(c)) {if(c=='-') w=-1; c=getchar();}
	while(isdigit(c)) {x=x*10+c-'0'; c=getchar();}
	return x*w;
}

const int N=1e5+9,inf=0x3f3f3f3f3f3f3f3f;
int deg[N],to[N],c[N],n,f[N][2],g[N][2][2],p[N],tot,vst[N],ans,sum,cnt1,cnt2;
vi e[N];

int work(int s,int ans=0) {
	p[++tot]=s;
	rep(i,0,tot+1) rep(a,0,1) rep(b,0,1) g[i][a][b]=0; g[1][1][1]=g[1][0][1]=-inf;
	rep(i,2,tot) {
		g[i][0][0]=max(g[i-1][0][0],g[i-1][1][1])+f[p[i]][0]+c[p[i-1]];
		g[i][0][1]=max(g[i-1][0][1],g[i-1][1][1])+f[p[i]][0]+c[p[i-1]];
		g[i][1][1]=max(max(g[i-1][0][0],g[i-1][0][1]),g[i-1][1][1])+max(f[p[i]][1],f[p[i]][0]);
	}
	ans=max(ans,g[tot][0][1]);
	rep(i,0,tot+1) rep(a,0,1) rep(b,0,1) g[i][a][b]=0; g[1][0][0]=g[1][0][1]=-inf;
	rep(i,2,tot) {
		g[i][0][0]=max(g[i-1][0][0],g[i-1][1][1])+f[p[i]][0]+c[p[i-1]];
		g[i][0][1]=max(g[i-1][0][1],g[i-1][1][1])+f[p[i]][0]+c[p[i-1]];
		g[i][1][1]=max(max(g[i-1][0][0],g[i-1][0][1]),g[i-1][1][1])+max(f[p[i]][1],f[p[i]][0]);
	}
	ans=max(ans,g[tot][1][1]);
	return ans;
}

void dfs(int u) {
	for(int v:e[u]) if(!deg[v]) {
		dfs(v); int g=max(f[v][0],f[v][1]);
		f[u][0]+=g;
		f[u][1]=max(f[u][1]+g,f[u][0]+c[v]);
	}
}

signed main() {
	n=read();
	rep(i,1,n) to[i]=read(), c[i]=read(), sum+=c[i];
	rep(i,1,n) e[to[i]].eb(i), deg[to[i]]++;
	queue<int>q; rep(i,1,n) if(!deg[i]) q.push(i);
	while(!q.empty()) {
		int u=q.front(); q.pop(); ++cnt1;
		if(!--deg[to[u]]) q.push(to[u]);
	}
	rep(i,1,n) if(deg[i]) dfs(i);
	rep(i,1,n) if(deg[i]&&!vst[i]) {
		int u=i; tot=0; ++cnt2;
		while(!vst[u]) vst[u]=1, p[++tot]=u, u=to[u];
		ans+=work(i);
	}
	if(cnt1==0&&cnt2==1) puts("0");
	else printf("%lld\n",sum-ans);
	return 0;
}