program evo;

{$APPTYPE CONSOLE}

uses
  SysUtils;

var f1,f2:text;
s1,s2:string;
n,ost,temp,i:integer;
f:boolean;
begin
assign(f1,'evo.dat');
RESET(F1);
READLN(F1,n);
READLN(F1,S1);
READLN(F1,S2);
CLOse(f1);
WHILE  s1<>s2 do begin
f:=true;
if length(s1)<length(s2) then f:=false;
if length(s1)=length(s2) then begin
i:=1;
while (s1[i]=s2[i])and(i<=length(s1)) do i:=i+1;
if s1[i]<s2[i] then f:=false;
end;
//writeln(s1,' ',s2,' ',i, f,' ', length(s1),' ',length(s2));
//readln;

if f then begin
ost:=0;
for i:=1 to length(s1) do begin
temp:=(ord(s1[i])-48+ost*10) div 2;
ost:=(ord(s1[i])-48+ost*10) mod 2;
s1[i]:=chr(temp+48);
end;
if s1[1]='0' then delete(s1,1,1);
end else
begin
ost:=0;
for i:=1 to length(s2) do begin
temp:=(ord(s2[i])-48+ost*10) div 2;
ost:=(ord(s2[i])-48+ost*10) mod 2;
s2[i]:=chr(temp+48);

end;
if s2[1]='0' then delete(s2,1,1);
end;
end;
assign(f2,'evo.sol');
rewrite(f2);
writeln(f2,S1);
Close(f2);

  { TODO -oUser -cConsole Main : Insert code here }
end.