#include <algorithm>
#include <bitset>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <istream>
#include <queue>
#include <vector>
using ll = int;

const ll maxn=5e4+5,maxk=51,inf=1e9+7;
ll n,k,b[maxn];
std::vector<std::vector<int>> edg;
std::vector<std::vector<int>> classp;
ll vis[maxn];

struct P{
    ll now,step;
    inline bool operator<(const P&o)const{
        return step>o.step;
    }
};
#define printf
int main(){
    std::iostream::sync_with_stdio(false);
    std::cin.tie(nullptr);

    std::cin>>n>>k;
    edg.resize(k+1);
    classp.resize(k+1);
    for(ll i=1;i<=n;i++){
        std::cin>>b[i];
        classp[b[i]].emplace_back(i);
        vis[i]=inf;
    }
    for(ll i=1;i<=k;i++){
        for(ll j=1;j<=k;j++){
            char tmp;
            std::cin>>tmp;
            if(tmp=='1'){
                edg[i].emplace_back(j);
            }
        }
    }
    std::priority_queue<P> pq;
    pq.emplace(1,0);
    while(pq.size()){
        auto[now,step]=pq.top();
        pq.pop();
        if(vis[now]!=inf)continue;
        vis[now]=std::min(step,vis[now]);
        printf("dij now=%lld, step=%lld\n",now,step);
        if(now==n){
            std::cout<<step<<"\n";
            return 0;
        }
        for(ll i:edg[b[now]]){
            for(ll p:classp[i]){
                if(p==now)continue;
                printf("%lld goto %lld\n",b[now],i);
                ll nstep=step+std::abs(p-now);
                if(nstep>vis[p])continue;
                pq.emplace(p,step+std::abs(p-now));
            }
        }
    }
    std::cout<<"-1\n";
}