#include<bits/stdc++.h>
#define int   long long
#define ll long long
#define down cout<<'\n';
#define debug cout<<" cucuucucuuu",down
#define NHP     ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
#define modwwe  int t;cin>>t; while(t--)
#define bit(i,j) (i>>j&1)
#define sobit(a) __builtin_popcountll(a)
#define task "test"
#define fin(x) freopen(x".inp","r",stdin)
#define fou(x) freopen(x".ans","w",stdout)
#define pb push_back
#define mask(k) (1<<k)
#define mp make_pair
#define checktime   cerr << (double)clock() / CLOCKS_PER_SEC * 1000  << " ms";
using namespace std;
#define getchar_unlocked getchar

inline int scan()
{
    char c = getchar_unlocked();
    int x = 0;
    while (c < '0' || c > '9')
    {
        c = getchar_unlocked();
    }
    while (c >= '0' && c <= '9')
    {
        x = (x << 1) + (x << 3) + c - '0';
        c = getchar_unlocked();
    }
    return x;
}
void phongbeo();
const int inf = 2e18;
const ll mod2 = 998244353;
const int  mod1 = 998244353;
const ll base=67;
int add(int x,int y)
{
    if(x+y>=mod2) x-=mod2;
    if(x+y<0)x+=mod2;
    return x+y;
}
struct icd
{
    long double a;
    int b;
};
struct ib
{
    int a;
    int b;
};
struct ic
{
    int a, b, c;
};
struct id
{
    int a, b, c, d;
};
struct ie
{
    int a, b, c, d, e;

};
int n, m, s1, s2, s4, s3, sf, k, s5, s6, mx, s7, s8, s9, mx2, res, dem2 = 0, dem = 0, s33, dem3, dem4, mid, l2, r2, center;
int  i, s10, s12,k1,k2,k3,s11,lim,w,l,r,ans ;
int kk;
int el = 19;
main()
{
    if(fopen(task".inp","r"))
    {
        fin(task);
        fou(task);
    }
    NHP
    /// cin>>s1;
    //modwwe
    phongbeo(),down
    // checktime
}
int dp[100001][2][2];
bool g[100001];
int in[100001];
vector<int> topo;
int dp2[2][2];
int a[100001],b[100001],c[100001],d[100001];
bool cc[100001];
void dfs(int x)
{
    in[x]=1;
    if(in[a[x]]==1)
    {
        cc[a[x]]=1;
        g[x]=1;
    }
    if(in[a[x]]==0)
        dfs(a[x]);
    topo.pb(x);
    in[x]=2;
}
void phongbeo()
{
    cin>>n;
    for(int i=1; i<=n; i++)
        cin>>a[i]>>b[i]>>c[i]>>d[i];
    for(int i=1; i<=n; i++)
        if(!in[i])
            dfs(i);
    reverse(topo.begin(),topo.end());
    for(auto x:topo)
    {
        if(cc[x])dp[x][1][0]=dp[x][0][1]=-inf;
        /// if(x==1) cout<<dp[x][1][1]<<" "<<dp[x][0][0],down
        if(g[x])
        {
            s5=0;
            for(int f=0; f<=1; f++)
                for(int f2=0; f2<=1; f2++)
                {
                    int cost;
                    int y=a[x];
                    if(f==f2) cost=b[x]*c[y];
                    else cost=b[x]*d[y];
                    s5=max(s5,dp[x][f][f2]+cost);
                }
            s4+=s5;
            continue;
        }
        for(int f=0; f<=1; f++)
            for(int f2=0; f2<=1; f2++)
                for(int f3=0; f3<=1; f3++)
                {
                    if(dp[x][f][f3]==-inf) continue;
                    int cost;
                    int y=a[x];
                    if(f==f2) cost=b[x]*c[y];
                    else cost=b[x]*d[y];
                    ///if(x==5&&f3==1&&f2==1) cout<<b[x]<<" "<<y<<" "<<d[y]<<" "<<c[y],down
                    dp2[f2][f3]=max(dp2[f2][f3],cost+dp[x][f][f3]);
                }
        int y=a[x];
        for(int f2=0; f2<=1; f2++)
            for(int f3=0; f3<=1; f3++)
                dp[y][f2][f3]+=dp2[f2][f3],dp2[f2][f3]=0;
    }
    cout<<s4;
}