var f:text;
function sum:real;
var num:real;
begin
sum := 0;
while not eof(f) do try
read (f, num);
if num<0 then sum:=0.0
else sum:=num+sum;
except end;
end;

const fn='data.txt';
n=5;
var res:real;
i:integer;
s:string;

begin
assign (f, fn);

repeat
writeln ('Содержимое файла: ');
rewrite (f);
randomize;

for var j: integer := 1 to n do begin
res:=1+random(100)/10;
writeln (f, res);
if j>1 then write (',');
write (res:0:1);
end;

writeln (f, 0);
writeln (',',0);

close(f);

reset(f);
res:=sum;
close (f);
writeln ('summa =', res:0:1);

writeln ('Повторить - Enter, Выход - Любой символ + Enter');
readln (s);
until s<>'';

end.