10702.cpp

 //BISMILLAHIRRAHMANIRRAHIM
/*
 manus tar shopner soman boro
 Author :: Shakil Ahmed
.............AUST_CSE27.........
 prob   ::
 Type   ::
 verdict::
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <math.h>
#include <limits.h>
#include <set>
#include <algorithm>
#include <iostream>
#include <vector>
#include <stack>
#include <string>
#include <list>
#include <map>
#include <queue>
#include <sstream>
#include <utility>
#define pb push_back
#define mp make_pair
#define pi acos(-1.0)
#define ff first
#define LL long long
#define ss second
#define rep(i,n) for(i = 0; i < n; i++)
#define REP(i,n) for(i=n;i>=0;i--)
#define FOR(i,a,b) for(int i = a; i <= b; i++)
#define ROF(i,a,b) for(int i = a; i >= b; i--)
#define re return
#define QI queue<int>
#define SI stack<int>
#define pii pair <int,int>
#define MAX
#define MOD
#define INF 1<<30
#define SZ(x) ((int) (x).size())
#define ALL(x) (x).begin(), (x).end()
#define sqr(x) ((x) * (x))
#define memo(a,b) memset((a),(b),sizeof(a))
#define G() getchar()
#define MAX3(a,b,c) max(a,max(b,c))

double const EPS=3e-8;
using namespace std;


template< class T > T gcd(T a, T b) { return (b != 0 ? gcd<T>(b, a%b) : a); }
template< class T > T lcm(T a, T b) { return (a / gcd<T>(a, b) * b); }
template <class T> inline T bigmod(T p,T e,T M)
{
    if(e==0)return 1;
    if(e%2==0){LL t=bigmod(p,e/2,M);return (T)((t*t)%M);}
    return (T)((LL)bigmod(p,e-1,M)*(LL)p)%M;
}

template <class T> inline T modinverse(T a,T M){return bigmod(a,M-2,M);}
//Fast Reader
template<class T>inline bool read(T &x){int c=getchar();int sgn=1;while(~c&&c<'0'||c>'9'){if(c=='-')sgn=-1;c=getchar();}for(x=0;~c&&'0'<=c&&c<='9';c=getchar())x=x*10+c-'0'; x*=sgn; return ~c;}

/* **************************************  My code start here ****************************************** */
const int N = 104;
bool EndCity[N];
int city , source , n , m ;
int inp[N][N];
int dp[N][10*N];
int DP(int cur ,int rem)
{
    int &ret = dp[cur][rem];
    if(ret != -1) return ret ;
    ret = -INF ;
    int i ;
    // base case
    if(rem==1)
    {
        for(i=0;i<city;i++)
        {
            if(EndCity[i]) ret = max(ret , inp[cur][i] );
        }
    }
    else
    {
        for(i=0;i<city;i++) ret = max ( ret , inp[cur][i] + DP(i,rem-1));
    }
    return ret;
}
int main()
{
    while(1)
    {
        read(city) , read(source) , read(n) , read(m) ;
        if( !city && !source && !n && !m) break;
        int i , j  , x;

        rep(i,city+2 ) { rep(j,m+2) dp[i][j] = -1; EndCity[i] = 0 ; }
        rep(i,city)
        {
            rep(j,city)
            {
                read(x);
                inp[i][j] = x ;
            }
        }
        rep(i,n)
        {
            read(x);
            x--;
            EndCity[x] = 1 ;
        }
        printf("%d\n",DP(source-1,m));
    }
   return 0;
}