#include <iostream>
#include <string>
#include <algorithm>
#include <unordered_set>

using namespace std;

int main()
{
   string s = "AllPossibleSubstrings";
   int l=0,index=0;
   for(int i =0;i<s.length();i++)
   {
       for(int j=i+1;j<s.length();j++)
       {
           string sub = string(s.begin()+i,s.begin()+j);
           unordered_set<char> v;
           for(auto x:sub)
           {
               v.insert(x);
           }
           if(v.size()<=2) {
           	l=max(l,j-i+1); 
           	if(l==j-i+1) {
           		index=i;
           		cout << "Found match " << i << " " << j << " " << l << " " << sub << endl;
           	}
           }
       }
   }

   cout<<l<<" "+s.substr(index,l)<<endl;

}