LINK：洞穴攀行
题目有鬼了。。
注意理解时间的含义 并非同一时刻而是指某次训练。
所以可以发现是最大流。
//#include<bitsstdc++.h>
#include<iostream>
#include<iomanip>
#include<cstdio>
#include<cstring>
#include<string>
#include<ctime>
#include<cmath>
#include<cctype>
#include<cstdlib>
#include<queue>
#include<deque>
#include<stack>
#include<vector>
#include<algorithm>
#include<utility>
#include<bitset>
#include<set>
#include<map>
#define ll long long
#define db double
#define INF 1000000000
#define ldb long double
#define pb push_back
#define get(x) x=read()
#define gt(x) scanf("%d",&x)
#define put(x) printf("%d
",x)
#define putl(x) printf("%lld
",x)
#define gc(a) scanf("%s",a+1)
#define rep(p,n,i) for(RE int i=p;i<=n;++i)
#define go(x) for(int i=lin[x],tn=ver[i];i;tn=ver[i=nex[i]])
#define fep(n,p,i) for(RE int i=n;i>=p;--i)
#define pii pair<int,int>
#define mk make_pair
#define mod 998244353
#define RE register
#define gf(x) scanf("%lf",&x)
#define pf(x) ((x)*(x))
#define ull unsigned long long
#define P 1000000000000000ll
using namespace std;
char buf[1<<15],*fs,*ft;
inline char getc()
{
return (fs==ft&&(ft=(fs=buf)+fread(buf,1,1<<15,stdin),fs==ft))?0:*fs++;
}
inline int read()
{
RE int x=0,f=1;char ch=getc();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getc();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getc();}
return x*f;
}
const int MAXN=210;
int n,m,S,len=1,T,L,R,ans;
int cur[MAXN],vis[MAXN],q[MAXN*MAXN<<1];
int lin[MAXN],ver[MAXN*MAXN<<1],nex[MAXN*MAXN<<1],e[MAXN*MAXN<<1];
inline void add(int x,int y,int z)
{
ver[++len]=y;nex[len]=lin[x];lin[x]=len;e[len]=z;
ver[++len]=x;nex[len]=lin[y];lin[y]=len;e[len]=0;
}
inline int dinic(int x,int flow)
{
if(x==T)return flow;
int res=flow,k;
for(int i=cur[x];i&&res;i=nex[i])
{
int tn=ver[i];cur[x]=i;
if(vis[tn]==vis[x]+1&&e[i])
{
k=dinic(tn,min(e[i],res));
if(!k){vis[tn]=0;continue;}
e[i]-=k;e[i^1]+=k;res-=k;
}
}
return flow-res;
}
inline int bfs()
{
rep(1,T,i)vis[i]=0,cur[i]=lin[i];
L=R=0;q[++R]=S;vis[S]=1;
while(++L<=R)
{
int x=q[L];
go(x)
{
if(vis[tn]||!e[i])continue;
vis[tn]=vis[x]+1;
q[++R]=tn;
if(tn==T)return 1;
}
}
return 0;
}
int main()
{
//freopen("1.in","r",stdin);
get(n);S=1;T=n;
rep(1,n-1,i)
{
int get(x),y;
rep(1,x,j)get(y),add(i,y,(i==1||y==n)?1:INF);
}
int flow,sum=0;
while(bfs())while((flow=dinic(S,INF)))sum+=flow;
put(sum);
return 0;
}