program stek11;
type
ttype = integer;

ptitem = ^titem;
titem = object
info: ttype;
next: ptitem;

constructor init(x: ttype; nxt: ptitem);
destructor done;
end;

constructor titem.init(x: ttype;
nxt: ptitem);
begin
info := x;
next := nxt
end;
destructor titem.done;
begin end;

type
pttype = ^ttype;
tstack = object
head: ptitem;

constructor init;
destructor done;

procedure push(x: ttype);
function pop: ttype;
function top: ttype;

function empty: boolean;

procedure print;
end;

constructor tstack.init;
begin
head := nil;
end;
destructor tstack.done;
begin
while not empty do pop
end;

procedure tstack.push(x: ttype);
var p: ptitem;
begin
new(p, init(x, head));
head := p
end;

function tstack.pop: ttype;
var p: ptitem;
begin
pop := -1;
if not empty then begin
p := head;
head := head^.next;

pop := p^.info;
dispose(p, done);
end
else begin
writeln('reading from empty stack');
halt(101)
end;
end;

function tstack.top: ttype;
begin
if empty then top := maxInt
else top := head^.info;
end;

function tstack.empty: boolean;
begin
empty := not assigned(head)
end;

procedure tstack.print;
var p: ptitem;
begin
p := head;
write('(stack) <');
while assigned(p) do begin
write(p^.info, ' ');
p := p^.next
end;
writeln('>')
end;

procedure sort_stack(var st: tstack);

var changed: boolean;

procedure deface(var new_st: tstack; next: ttype);
var X: ttype;
begin
if not new_st.empty then begin
X := new_st.pop;
deface(new_st, X);
end;

if new_st.top < next then begin
X := new_st.pop;
new_st.push(next);
new_st.push(X);
changed := true;
end
else new_st.push(next);
end;

begin
repeat
changed := false;
deface(st, st.pop);
until not changed;
end;


function max_stack(var st: tstack): ttype;

var max_value: ttype;

procedure deface(var new_st: tstack; next: ttype);
var X: integer;
begin
if not new_st.empty then begin
X := new_st.pop;
if max_value < X then max_value := X;
deface(new_st, X);
end;
new_st.push(next);
end;

begin
max_value := st.top;
deface(st, st.pop);
max_stack := max_value;
end;

var
st_arr: array[1 .. 4] of tstack;
i, j, k, X: integer;

begin
for i := 1 to 3 do begin
st_arr[i].init;
k := random(1) + 5;
writeln('vvedite ', k, ' elementov ', i, '-go steka:');
for j := 1 to k do begin
write(' -> '); readln(X); st_arr[i].push(X);
end;
end;

st_arr[4].init;
for i := 1 to 3 do begin
writeln('#', i); st_arr[i].print;
st_arr[4].push(max_stack(st_arr[i]));
end;

sort_stack(st_arr[4]);
writeln('#4'); st_arr[4].print;
end.