Program HOC24;

var s: string;

tg,d,max,i: byte;

code: integer;

begin

write('Nhap xau : '); readln(s);

// cau a

for i:=1 to length(s) do if s[i] in ['a'..'z'] then write(upcase(s[i]));

//------

writeln;

//-cau b

for i:=length(s) downto 1 do if s[i] in ['0'..'9'] then write(s[i]);

//------

writeln;

//---cau c

d:=0;

for i:= 1 to length(s) do

if s[i] in ['0'..'9'] then 

begin

val(s[i],tg,code);

if tg>max then max:=tg;

d:=d+1;

end;

if d=0 then write('Khong co chu so trong day') else write('Chu so lon nhat la : ',max);

readln 

end.

uses crt;

var st,st1:string;

d,i,d1,max,x,y:integer;

begin

clrscr;

write('Nhap xau:'); readln(st);

d:=length(st);

writeln('Day cac ki tu thuong doi sang chu hoa la: ');

for i:=1 to d do 

  if st[i] in ['a'..'z'] then write(upcase(st[i]):4);

st1:='';

for i:=1 to d do 

  if st[i] in ['0'..'9'] then st1:=st1+st[i];

d1:=length(st1);

for i:=d1 downto 1 do 

  write(st1[i]:4);

writeln;

max:=0;

for i:=1 to d1 do 

  begin

val(st1[i],x,y);

if max<x then max:=x;

end;

writeln('Chu so lon nhat trong xau la: ',max);

readln;

end.

uses crt;

var s,s1,s2:string;

i,d:integer;

begin

clrscr;

readln(s);

s1:='';

s2:='';

d:=length(s);

for i:=1 to d do

  begin

if s[i] in ['0'..'9'] then s1:=s1+s[i];

if (s[i] in ['a'..'z']) or (s[i] in ['A'..'Z']) then s2:=s2+s[i];

end;

writeln('Xau chua cac ki tu so la: ',s1);

writeln('Xau chua cac ki tu chu la: ',s2);

readln;

end.

uses crt;

var st:string;

i,d:integer;

begin

clrscr;

write('Nhap xau:'); readln(st);

d:=length(st);

writeln('Xau vua nhap la: ',st);

for i:=1 to d do 

  if st[i] in ['a'..'z'] then upcase(st[i]);

writeln(st);

readln;

end.

program ChuyenXauSangChuThuong;
var
  str: string; 
  i: integer; 

begin
  write('Nhap mot xau ky tu: ');
  readln(str); 
  for i := 1 to Length(str) do
    str[i] := LowerCase(str[i]); 
  writeln('Xau ky tu chuyen thanh chu thuong la: ', str); 
end.

uses crt;

var s:string;

i,d,dem1,dem2,dem3,dem4:integer;

begin

clrscr;

write('Nhap xau s:'); readln(s);

d:=length(s);

dem1:=0;

dem2:=0;

dem3:=0;

dem4:=0;

for i:=1 to d do 

  begin

if st[i] in ['0'..'9'] then inc(dem1)

else if st[i] in ['a'..'z'] then inc(dem2)

else if st[i] in ['A'..'Z'] then inc(dem3)

else inc(dem4);

end;

writeln('So luong ky tu so la: ',dem1);

writeln('So luong ky tu thuong la: ',dem2);

writeln('So luong ky tu hoa la: ',dem3);

writeln('So luong ky tu dac biet la: ',dem4);

readln;

end.

Program HOC24;

var s: string;

i: byte;

begin

write('Nhap xau: '); readln(s);

for i:=1 to n do if not(s[i] in ['0'..'9']) then write(s[i]);

readln

end.

uses crt;

var st:string[50];

d,i:integer;

begin

clrscr;

write('Nhap xau:'); readln(st);

d:=length(st);

for i:=1 to d do 

  if st[i] in ['a'..'z'] then write(st[i]:4);

readln;

end.