program tong_ki_tu;
uses crt;
var st: string;
function tcs( st: string) : boolean;
var i, chuso, tong : integer;
begin
tong:=0;
for i:= 1 to length(st) do
begin
val( st, chuso);
tong:= tong + chuso;
end;
tcs:= tong;
end;
begin
clrscr;
write(' nhap chuoi ki tu : ');
readln(st);
write(' tong chu so co trong chuoi ',st,' : ',tcs(st));
readln;
end.