1/
uses crt;
var s:string;
i:byte;
begin
clrscr;
write('Nhap xau: '); readln(s);
while i<=length(s) do
begin
s[i]:=upcase(s[i]);
if (s[i] in ['0'..'9']) or (s[i]=' ') then
begin
delete(s,i,1);
dec(i);
end;
inc(i);
end;
write('Xau ket qua la: ',s);
readln
end.
2/
uses crt;
var s:string;
i:byte;
begin
clrscr;
write('Nhap xau: '); readln(s);
for i:=1 to length(s) do
if s[i]='a' then
begin
delete(s,i,1);
insert('t',s,i);
end;
write('Xau ket qua la: ',s);
readln
end.
