Write a program that displays all four-digit numbers whose sum is less than 4 pascal.

program chisla;
var
i, ch: integer;
a, c, d, b, s: byte;
begin
for i: = 1000 to 9999 do begin
s: = 0; ch: = i;
a: = ch mod 10;
ch: = ch div 100;
b: = ch mod 10;
c: = ch div 100;
d: = i div 1000;
writeln (d);
s: = a + c + d + b;
if s <4 then begin
writeln (‘The numbers of the sum of digits that have less than 4’);
writeln (i) end else break;
end;
end.