Программа просит идентификатор

Program density;
var (weight, capacity , density :integer);
begin {начало программы}
writeln ('Please enter weight');
readln (weight);
writeln ('Please enter capacity');
readln (capacity);
densety:=weight "/" capacity;
end. {конец программы}

Program density;
var weight, capacity , density :REAL;
BEGIN {начало программы}
writeln ('Please enter weight');
readln (weight);
writeln ('Please enter capacity');
readln (capacity);
density:=weight / capacity;
END. {конец программы}

Program den;
uses crt;
var weight, capacity  :INTEGER;
density: real;
BEGIN {начало программы}
writeln ('Please enter weight');
readln (weight);
writeln ('Please enter capacity');
readln (capacity);
density:=weight/capacity;
writeln(density);
END. {конец программы}

writeln(density,'/',capacity);

program Kiker32;
 
var
  a, b, c: integer;
 
begin
  writeln('Please enter a');
  readln(a);
  writeln('Please enter b');
  readln(b);
  c := (a + b) * (a + b);
  writeln(c);
end.

uses crt;
var
a,b,n,s: integer;
begin
writeln('Выберите формулу:');
writeln('1) (a+b)*(a+b);');
writeln('2) (a-b)*(a-b);');
writeln('3) (a+b)*(a-b);');
repeat
read(n);
until n in [1..3];
writeln('Введите a и b:');
read(a,b);
case n of
1: s:=(a+b)*(a+b);
2: s:=(a-b)*(a-b);
3: s:=(a+b)*(a-b);
end;
write('Ответ: ',s);
end.