#include<bits/stdc++.h>

using namespace std;

#define MAXN 2000

#define MAXB 1000

int i,j,low,high,mid,st,ed,N,B,tot,ans,tmp;

int h[MAXN+MAXB],U[MAXN*MAXB],V[MAXN*MAXB],

   W[MAXN*MAXB],Head[MAXN*MAXB],Next[MAXN*MAXB],

     other[MAXN*MAXB],v[MAXB+],a[MAXN+][MAXB+];

template <typename T> void read(T &x) {

        int f=; char c = getchar(); x=;

        for (; !isdigit(c); c = getchar()) { if (c=='-') f = -f; }

        for (; isdigit(c); c = getchar()) x=x*+c-'';

        x*=f;

}

template <typename T> inline void write(T x) {

        if (x < ) { putchar('-'); x = -x; }

        if (x > ) write(x/);

        putchar(x %  + '');

}

template <typename T> inline void writeln(T x) {

        write(x);

        puts("");

}

inline void add(int a,int b,int c) {

        ++tot;

        U[tot] = a; V[tot] = b; W[tot] = c;

        Next[tot] = Head[a]; Head[a] = tot;

        other[tot] = ++tot;

        U[tot] = b; V[tot] = a; W[tot] = ;

        Next[tot] = Head[b]; Head[b] = tot;

        other[tot] = tot - ;

}

inline bool bfs() {

        int i,x,y;

        queue<int> q;

        memset(h,,sizeof(h));

        h[st] = ; q.push(st);

        while (!q.empty()) {

                x = q.front(); q.pop();

                for (i = Head[x]; i; i = Next[i]) {

                        y = V[i];

                        if ((W[i] > ) && (!h[y])) {

                                h[y] = h[x] + ;

                                q.push(y);

                        }

                }

        }

        if (h[ed]) return true;

        else return false;

}

inline int maxflow(int x,int f) {

        int i,t,y,sum=;

        if (x == ed) return f;

        for (i = Head[x]; i; i = Next[i]) {

                y = V[i];

                if ((W[i] > ) && (h[y] == h[x] + ) && (sum < f)) {

                        sum += (t = maxflow(y,min(W[i],f-sum)));

                        W[i] -= t; W[other[i]] += t;

                }

        }

        if (!sum) h[x] = ;

        return sum;

}

inline bool check(int ml) {

        int i,j,l,r,sum;

        for (l = ; l <= N - ml + ; l++) {

                r = l + ml - ;

                for (i = ; i <= tot; i++) Head[i] = ;

                tot = ;

                for (i = ; i <= N; i++) add(st,i,);

                for (i = ; i <= B; i++) add(i+N,ed,v[i]);

                for (i = ; i <= N; i++) {

                        for (j = ; j <= B; j++) {

                                if ((a[i][j] >= l) && (a[i][j] <= r))

                                        add(i,j+N,);

                        }

                }

                sum = ;

                while (bfs()) {

                        sum += maxflow(st,N);

                }

                if (sum == N) return true;

        }

        return false;

}

int main() {

        read(N); read(B);

        st = N + B + ; ed = st + ;

        for (i = ; i <= N; i++) {

                for (j = ; j <= B; j++) {

                        read(tmp);

                        a[i][tmp] = j;

                }

        }

        for (i = ; i <= B; i++) read(v[i]);

        low = ; high = B;

        while (low <= high) {

                mid = (low + high) / ;

                if (check(mid)) {

                        high = mid - ;

                        ans = mid;

                } else

                        low = mid + ;

        }

        writeln(ans);

        return ;

}