Pascal问题两则.>

1.
var s,ss:string;
l,i:integer;
begin
readln(s);
l:=length(s);
ss:='';
for i:=1 to l do
if s[i]<>'B'then ss:=ss+s[i]
else ss:=ss+'34'
writeln(ss);
end.

2.
var s:string;
l,i:integer;
begin
readln(s);
l:=length(s);
for i:=l downto 1 do
write(s[i]);
end.

1、
var
begin
read(a);
k:=length(a);
for i:=1 to k do
if a[i]='B' then a:=copy(a,1,i-1)+'34'+copy(a,i+1,k);
writeln(a);
end.
2、
var a:string;
k,i:integer;
begin
read(a);
k:=length(a);
for i:=1 to k do
write(a[k+1-i]);
end.

1.
program a1;
var s,s1,s2:string;
i:integer;
begin
readln(s);
for i:=1 to length(s) do if s[i]='B' then begin
s1:=copy(s,1,i-1);
s2:=copy(s,i+1,length(s)-i);
s:=s1+'34