#include<bits/stdc++.h>
#define rep(x,y,z) for(int x=y;x<=z;x++)
#define drep(x,y,z) for(int x=y;x>=z;x--)
#define ull unsigned long long
#define ll long long
using namespace std;
inline int read()
{
	int x=0;bool flag=1;char ch=getchar();
	while(ch<'0'||ch>'9') {if(ch=='-')flag=0;ch=getchar();}
	while(ch>='0'&&ch<='9') {x=(x<<3)+(x<<1)+ch-'0';ch=getchar();}
	if(flag) return x;
	return ~(x-1);
} 
inline void write(int x)
{
	if(x<0) {x=~(x-1);putchar('-');}
	if(x>9) write(x/10);
	putchar(x%10+'0');
}
//////////////////////////////////////////
const int N=1e6+50;
int nc; 
struct TREE
{
	ll sum;
	ll mx;
}a[N];
int hd[N];
struct qxx
{
	int ar;
	int nx;
	int val;
}l[N];
int lj;
inline void ADD(int x,int y,int p)
{
	l[++lj].ar=y;
	l[lj].val=p;
	l[lj].nx=hd[x];
	hd[x]=lj;
}
void dfs(int cl)
{
	if(!hd[cl]) return;
	for(int i=hd[cl];i;i=l[i].nx)
	{
		dfs(l[i].ar);
		a[cl].sum=max(a[cl].sum,max(a[cl].mx+a[l[i].ar].mx+l[i].val,a[l[i].ar].sum+l[i].val));
		a[cl].mx=max(a[l[i].ar].mx+l[i].val,a[cl].mx);
	}
}
int main()
{
    freopen("galgame.in","r",stdin);
	freopen("galgame.out","w",stdout);
    nc=read();
    int s1,s2,s3;
    rep(i,1,nc)
    {
    	s1=read();
    	rep(o,1,s1)
    	{
    		s2=read(),s3=read();
    		ADD(i,s3,s2);
		}
	}
	dfs(1);
//	rep(i,1,nc)
//	{
//		cout<<i<<":"<<a[i].sum<<"  "<<a[i].mx<<endl;
//	}
	cout<<a[1].sum<<endl;
    return 0;
}