//```// YF YUSUF
#include <bits/stdc++.h>
// #include <iostream>
// #include <vector>
// #include <set>
// #include <map>
// #include <algorithm>
// #include <cmath>
// #include <numeric>
// #include <queue>
// #include <stack>
// #include <cassert>
// #include <climits>
// #include <string>
// #include <cstdlib>
// #include <random>
// #include <iomanip>
// #include <ctime>
using namespace std;
#ifdef YF_CHECK
bool LOCAL = 1;
#else
#pragma GCC optimize ("unroll-loops")
#pragma GCC optimize ("inline")
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("O3")
bool LOCAL = 0;
#endif
using ll = long long;
using ld = long double;
using vll = vector <ll>;
using mll = map <ll,ll>;
using pll = pair <ll,ll>;
using vvl = vector <vll>;
using vpll = vector <pll>;
template<class T>T MIN(T&a,T b){a=min(a,b);return a;}
template<class T>T MAX(T&a,T b){a=max(a,b);return a;}
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define sgr v+v+1,(tl+tr)/2+1,tr
#define sgl v+v,tl,(tl+tr)/2
#define pb push_back
#define ins insert
#define S second
#define F first
mt19937_64 MT(time(0));
ll BP(ll a,ll b,ll mod=1e9+7){
if(b==0)return 1;
ll q=BP(a,b/2,mod);
return ((q*q)%mod*(b%2?a:1ll))%mod;
}
ll f(ll x){return x*(x+1)/2;}
ll dup(ll a,ll b){return (a+b-1)/b;}
ll lcm(ll a,ll b){return a/__gcd(a,b)*b;}
ll invf(ll x){return (-1+sqrt(1+8*x))/2;}
ll lg(ll x){return (x ? 63 - __builtin_clzll(x) : -1);}
const ll mod=998244353;
const ll INF=1e18;
const ll inf=1e9+7;
const ll N =1e6+7;
ll slow_cnk(ll n,ll k){
MIN(k, n-k);
ll ans = 1;
for (int i = 1; i <= k; i++)
ans = (ans * (n-k+i) / i);
return ans;
}
ll get(ll n,ll m){
return slow_cnk(n+m-2, min(n-1, m-1));
}
ll n, m, k;
ll GET(ll i,ll j){
return get(n-i+1, m-j+1);
}
void YF_MAIN(ll TEST){
cin>>n>>m;
string s[n];
for(int i=0;i<n;i++)
cin>>s[i];
while(cin>>k){
ll i=0, j=0;
string ans;ans+=s[i][j];
while(i < n-1 && j < m-1){
ll A = GET(1+i+1, 1+j);
ll B = GET(1+i, 1+j+1);
// cout<<i<<" "<<j<<": "<<A<<" "<<B<<" "<<k<<"\n";
if(s[i+1][j] < s[i][j+1]){
if(A >= k){
i++;
// j++;
} else{
k -= A;
j++;
// i++;
}
}
else{
if(B >= k){
j++;
// i++;
} else{
k-=B;
i++;
// j++;
}
}
ans += s[i][j];
}
while(j<m-1){
j++;
ans+=s[i][j];
}
while(i<n-1){
i++;
ans+=s[i][j];
}
cout<<ans<<"\n";
}
}
const bool TECT=0;
const bool FLSH=0;
const ll SN=1e0 + 7; ll SM[SN];
const ll FN=1e0 + 7; ll FACT[FN], inv[FN], FMOD=inf;
ll PNK(ll n,ll k){return FACT[n] *inv[n-k]%FMOD;}
ll CNK(ll n,ll k){return PNK(n,k)*inv[k ]%FMOD;}
void BEFORE(){
for(ll i=2;i<SN;i++){
if(SM[i])continue;
for(ll j=i;j<SN;j+=i)
MAX(SM[j],i);
}
FACT[0]=inv[0]=1;
for(int i=1;i<FN;i++){
FACT[i]=FACT[i-1]*i%FMOD;
inv[i]=BP(FACT[i],FMOD-2,FMOD);
}
}
signed main(){
// freopen(("input.txt"),"r",stdin);freopen(("output.txt"),"w",stdout);
if(FLSH){
ios_base::sync_with_stdio(0);
cout.setf(ios::fixed);
cout.precision(0);
cout.tie(0);
cin.tie(0);
}
int TEST=1;
if(TECT)
cin>>TEST;
BEFORE();
for(int T=1;T<=TEST;T++){
// cout<<"Case "<<T<<": ";
YF_MAIN(T);
cout<<(T==TEST ? "" : "\n");
}
return 0;
}
// YF YUSUF ```
