///jai sri krishna
///jai maa kali


#include<bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace __gnu_pbds;


typedef long long ll;
typedef long double ld;
typedef tree<
ll,
null_type,
less_equal<ll>,
rb_tree_tag,
tree_order_statistics_node_update>
ordered_set;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

#define db double
#define pii pair<ll,ll>
#define f(i,a,b) for(ll i=a;i<b;i++)
#define fi(i,a,b,c) for(ll i=a;i<b;i+=c)
#define fr(i,a,b) for(ll i=a;i>=b;i--)
#define fri(i,a,b,c) for(ll i=a;i>=b;i-=c)
#define pb push_back
#define ss second
#define ff first
#define in insert
#define sq(x)  (x*x)
#define all(a)  a.begin(),a.end()
#define nl "\n"
#define mnpq  priority_queue <pii, vector<pii>, greater<pii> >

ll gcd(ll a,ll b){
       if(b==0)return a;
       return gcd(b,a%b);
}
int getRandom(int L,int R)
{
    return rng()%(R-L+1) + L;
}

ll lcm(ll a,ll b){
       return ((a)/gcd(a,b))*b;
}

ll bigmod(ll a,ll n,ll md){
       if(n==0){
           return 1;
       }
       if(n==1){
           return a%md;
       }
       ll d= bigmod(a,n/2,md);
       if(n%2==0){
           return (d*d)%md;
       }
       else{
           return ( ((d*d)%md) * (a%md) )%md;
       }
}

bool sortbysec(const pair<int,int> &a,
            const pair<int,int> &b)
{

    if(a.first==b.first){
         return (a.second > b.second);
    }

    return (a.first< b.first);
}


const ll  N = 103000;
const ll mod = 998244353;

const ll neginf= -1e18;
const ll inf = 1e9;
const ld eps= 1e-9;

/// Solve part by part
/// Think small case
/// Think reverse order
/// Take best solution


/// test against atleast 10 cases

/// give 10 min before submission
/// wrong submission 20 min penalty


/// use binary search for maximum minimum problem
/// use broute force to check test case in another solution


int main(){

       ios_base::sync_with_stdio(false);
       cin.tie(NULL);
       cout.tie(NULL);

      ll t;
      cin>>t;
      f(i,1,t+1){

          ll n,m;
          cin>>n>>m;
          string ss,tt;
          cin>>ss>>tt;
          string rr;
          cin>>rr;

          ll d1=(ss[0]-'A');
          ll d2=(tt[0]-'A')+26;

          ll df=(d2-d1);

          string res="";
          f(j,0,rr.size()){
              ll d=rr[j]-'A';
              d-=df;

              while(d<0){
                d+=26;
              }

              char ch=d+'A';
              res+=ch;
          }

          cout<<"Case "<<"#"<<i<<": ";
          cout<<res<<nl;


      }

}