uses crt;
const
n = 50;
var
a: array [1 .. n] of integer;
i: byte;
sum: integer;
begin
sum := 0;
randomize;
clrscr;
writeln('исходный массив: ');
for i := 1 to n do
begin
a[i] := random(19) - 9;
write(a[i]:3);
if i mod 20 = 0 then
writeln;
end;
writeln;
for i := 1 to n do
if (a[i] = 4) or (a[i] = 7) then
inc(sum, a[i]);
writeln('сумма элементов = ', sum);
end.