#include<bits/stdc++.h>
#include<combo.h>
#define ll long long
#define fi first
#define se second
using namespace std;
const size_t N=2e3+10;
string s;
/*size_t press(string p){
size_t res=0;
for(size_t i=0;i<p.size();i++){
size_t j=i;
while(j-i<s.size()&&j<p.size()&&p[j]==s[j-i]) j++;
res=max(res,j-i);
}
return res;
}*/
string guess_sequence(int n){
string curr="";
string k1,k2,k3;
if(press("A")) curr="A",k1="Y",k2="X",k3="B";
else{
if(press("Y")) curr="Y",k1="X",k2="A",k3="B";
else{
if(press("B")) curr="B",k1="Y",k2="A",k3="X";
else curr="X",k1="Y",k2="A",k3="B";
}
}
size_t i;
for(i=2;(int)i<=n-2;){
size_t x=press(curr+k1+k2+k3+curr+k1+k1+k3+curr+k2+k1+k3);
if(x==0+curr.size()){curr+=k3,i++;continue;}
if(x==1+curr.size()){
size_t x2=press(curr+k1+curr+k2+k2+k3+curr+k2+k3+k3+curr+k2+k2+k1);
if(x2==curr.size()+1){curr+=k1+k3;i+=2;continue;}
if(x2==curr.size()+2){
size_t x3=press(curr+k2+k3+k1);
if(x3==curr.size()+1) curr+=k2+k2+k2;
else{
if(x3==curr.size()+2) curr+=k2+k3+k2;
else curr+=k2+k3+k1;
}
i+=3;
continue;
}
size_t x3=press(curr+k2+k2+k3);
if(x3==curr.size()+1) curr+=k2+k3+k3;
else{
if(x3==curr.size()+2) curr+=k2+k2+k1;
else curr+=k2+k2+k3;
}
i+=3;
continue;
}
if(x==2+curr.size()){
size_t x2=press(curr+k2+k1+curr+k1+k2+k1+curr+k1+k2+k2);
if(x2==curr.size()+1){
size_t x3=press(curr+k1+k1+k1);
if(x3==curr.size()+2) curr+=k1+k1+k2;
else curr+=k1+k1+k1;
i+=3;
continue;
}
if(x2==curr.size()+2){
size_t x3=press(curr+k2+k1+k1);
if(x3==curr.size()+2) curr+=k2+k1+k2;
else curr+=k2+k1+k1;
}else{
size_t x3=press(curr+k1+k2+k1);
if(x3==curr.size()+2) curr+=k1+k2+k2;
else curr+=k1+k2+k1;
}
i+=3;
continue;
}else{
size_t x2=press(curr+k1+k2+k3);
if(x2==curr.size()+3){curr+=k1+k2+k3;i+=3;continue;}
x2=press(curr+k1+k1+k3);
if(x2==curr.size()+3) curr+=k1+k1+k3;
else curr+=k2+k1+k3;
i+=3;
continue;
}
}
if((int)curr.size()==n-2){
size_t x=press(curr+k1+k2+curr+k2+k2);
if(x==curr.size()) curr+=k3;
else{
if(x==curr.size()+2){
size_t x2=press(curr+k1+k2);
if(x2==curr.size()+2) curr+=k1+k2;
else curr+=k2+k2;
}else{
size_t x2=press(curr+k1+k1+curr+k2+k1);
if(x2==curr.size()+2){
size_t x3=press(curr+k1+k1);
if(x3==curr.size()+2) curr+=k1+k1;
else curr+=k2+k1;
}else{
size_t x3=press(curr+k1);
if(x3==curr.size()+1) curr+=k1+k3;
else curr+=k2+k3;
}
}
}
}
if((int)curr.size()==n-1){
size_t x=press(curr+k1+curr+k2+k1+curr+k2+k2+curr+k2+k3);
if(x==curr.size()) curr+=k3;
else{
if(x==curr.size()+1) curr+=k1;
else{
if(x==curr.size()+2) curr+=k2;
}
}
}
return curr;
}
/*int main(){
cin>>s;
cout<<guess_sequence(s.size())<<"\n";
return 0;
}*/
