Var b, c, d : string;
a : array [1..255] of byte;
i, k, m : integer;
f1, f2 : text;
begin
assign(f1,'input.txt'); reset(f1);
readln(f1,b); readln(f1,c);
if length(b)<length(c) then
begin d:=b; b:=c; c:=d end;
for i:=1 to length(b)-length(c) do c:='0'+c;
m:=length(b);
for i:=1 to 255 do a[i]:=0;
for i:=1 to m do
a[i]:=ord(b[m+1-i])+ord(c[m+1-i])-96;
k:=1;
repeat
if k=1 then
begin
if a[1]>1 then
begin
a[1]:=0; if m<2 then m:=2; a[2]:=a[2]+1
end;
k:=k+1
end;
if k=2 then
begin
if a[2]<2 then
begin
if (a[2]=1) and (a[1]=1) then
begin
a[1]:=0; a[2]:=0; if m<3 then m:=3; a[3]:=a[3]+1
end;
k:=k+1
end
else
begin
if m<3 then m:=3; a[3]:=a[3]+1;
if a[1]=0 then
begin
a[1]:=a[1]+1; a[2]:=a[2]-2; k:=1
end
else
begin
a[1]:=0; a[2]:=a[2]-1;
end
end
end;
if k>2 then
if a[k]<2 then
begin
if (a[k-1]=1) and (a[k]=1) then
begin
a[k-1]:=0; a[k]:=0; if k+1>m then m:=k+1; a[k+1]:=a[k+1]+1
end;
k:=k+1
end
else
begin
if k+1>m then m:=k+1; a[k+1]:=a[k+1]+1;
if a[k-1]=0 then
begin
a[k-2]:=a[k-2]+1; a[k]:=a[k]-2; k:=k-2
end
else
begin
a[k-1]:=0; a[k]:=a[k]-1
end
end
until k>m;
assign(f2,'output.txt'); rewrite(f2);
for i:=m downto 1 do write(f2,a[i]); close(f2)
end.
a : array [1..255] of byte;
i, k, m : integer;
f1, f2 : text;
begin
assign(f1,'input.txt'); reset(f1);
readln(f1,b); readln(f1,c);
if length(b)<length(c) then
begin d:=b; b:=c; c:=d end;
for i:=1 to length(b)-length(c) do c:='0'+c;
m:=length(b);
for i:=1 to 255 do a[i]:=0;
for i:=1 to m do
a[i]:=ord(b[m+1-i])+ord(c[m+1-i])-96;
k:=1;
repeat
if k=1 then
begin
if a[1]>1 then
begin
a[1]:=0; if m<2 then m:=2; a[2]:=a[2]+1
end;
k:=k+1
end;
if k=2 then
begin
if a[2]<2 then
begin
if (a[2]=1) and (a[1]=1) then
begin
a[1]:=0; a[2]:=0; if m<3 then m:=3; a[3]:=a[3]+1
end;
k:=k+1
end
else
begin
if m<3 then m:=3; a[3]:=a[3]+1;
if a[1]=0 then
begin
a[1]:=a[1]+1; a[2]:=a[2]-2; k:=1
end
else
begin
a[1]:=0; a[2]:=a[2]-1;
end
end
end;
if k>2 then
if a[k]<2 then
begin
if (a[k-1]=1) and (a[k]=1) then
begin
a[k-1]:=0; a[k]:=0; if k+1>m then m:=k+1; a[k+1]:=a[k+1]+1
end;
k:=k+1
end
else
begin
if k+1>m then m:=k+1; a[k+1]:=a[k+1]+1;
if a[k-1]=0 then
begin
a[k-2]:=a[k-2]+1; a[k]:=a[k]-2; k:=k-2
end
else
begin
a[k-1]:=0; a[k]:=a[k]-1
end
end
until k>m;
assign(f2,'output.txt'); rewrite(f2);
for i:=m downto 1 do write(f2,a[i]); close(f2)
end.