var s,t:ansistring;

     n,op:longint;

     p:array[..] of longint;

 procedure pre;

 var i:longint;

 begin

     s:='$*';

     for i:= to length(t) do

     begin

         s:=s+t[i]+'*';

     end;

     s:=s+'#';

     n:=length(s);

 end;

 function min(a,b:longint):longint;

 begin

     if a<b then exit(a) else exit(b);

 end;

 procedure manacher;

 var i,mx,id:longint;

 begin

     fillchar(p,sizeof(p),);

     mx:=; id:=; p[]:=;

     for i:= to n do

     begin

         p[i]:=;

         if mx>i then p[i]:=min(mx-i,p[id*-i]);

         while s[i+p[i]]=s[i-p[i]] do inc(p[i]);

         if p[i]+i>mx then begin mx:=p[i]+i; id:=i; end;

     end;

 end;

 procedure print;

 var ans,i:longint;

 begin

     //writeln(s);

     ans:=;

     for i:= to n do if p[i]->ans then ans:=p[i]-;

     writeln('Case ',op,': ',ans);

 end;

 begin

     op:=;

     while true do

     begin

         inc(op);

         t:='';

         readln(t);

         if t='END' then break;

         pre;

         manacher;

         print;

     end;

 end.