/*************************************************************************
    > File Name: 5811.cpp
    > Author: jiangyuzhu
    > Mail: 834138558@qq.com 
    > Created Time: 2016/8/17 11:19:57
 ************************************************************************/
#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
#include<vector>
#include<set>
#include<map>
#include<algorithm>
using namespace std;
const int maxn = 1e3 + 5, oo = 0x3f3f3f3f;
int a[2][maxn];
bool vis[maxn];
int mp[maxn][maxn];
int n, m;
struct EDGE{
	int to,  next;
}edge[maxn * maxn];
int head[maxn];
int tid[2][maxn];
int tot;
int in[maxn];
int dp[maxn];
int b[maxn];
void init()
{
	memset(in, 0, sizeof(in));
	memset(head, -1, sizeof(head));
	tot = 0;
}
void addedge(int from, int to)
{
	in[to]++;
	edge[tot].to = to;
	edge[tot].next = head[from];
	head[from] = tot++;
}
bool Topology(int k)
{
	int tp = 0;
	queue<int>q;
	for(int i = 0; i < n; i++){
		if(in[i] == 0 && vis[i] != k){
			q.push(i);
		}
	}
	while(!q.empty()){
		int u = q.front();q.pop();
		tid[k][tp++] = u;
		for(int i = head[u]; i != -1; i = edge[i].next){
			in[edge[i].to]--;
			if(!in[edge[i].to]) q.push(edge[i].to);
		}
	}
	if(k) return tp == n - m;
	else return tp == m;
}
char s[maxn];
int main (void)
{
	while(~scanf("%d%d", &n, &m) && (n + m)){
		init();
		getchar();
		for(int i = 0; i < n; i++){
			gets(s);
			for(int j = 0; j < 2 * n; j += 2){
				mp[i][j / 2] = s[j] - '0';
			}
			vis[i] = false;
			dp[i] = oo;
		}
		int tota = 0, totb = 0;
		int x;
		for(int i = 0; i < m; i++){
			scanf("%d", &x);x--;
			a[0][tota++] = x;
			vis[x] = true;
		}
		for(int i = 0; i < n; i++){
			if(!vis[i]){
				a[1][totb++] = i;
			}
		}
		for(int i = 0; i < n; i++){
			for(int j = 0 ; j < n; j++){
				if(mp[i][j] && vis[i] == vis[j]){
					addedge(j, i);
				}
			}
		}
		if(!Topology(0) || !Topology(1)){
			puts("NO");
			continue;
		}
		int ans;
		for(int i = 0; i < n - m; i++){
			ans = -1;
			for(int j = 0; j < m; j++){
				if(mp[tid[0][j]][tid[1][i]]){
					ans = j;
					break;
				}
			}
			if(ans == -1) ans = m;
			for(int j = ans + 1; j < m; j++){
				if(mp[tid[1][i]][tid[0][j]]){
					ans = -1;
					break;
				}
			}
			if(ans == -1) continue;
			*upper_bound(dp, dp + n - m, ans) = ans;
		}
		printf("YES %d\n", lower_bound(dp, dp + n - m, oo) - dp);
	}
	return 0;
}