uses crt;
const n=10;
var
i,k:integer;
s:real;
m:array[1..n]of integer;
begin
clrscr;
for i:=1 to n do
m[i]:=random(50);
for i:=1 to n do
if((m[i]>0)and (i mod 2=1)) then begin
inc(k);
s:=s+m[i];
end;
write('Среднее арифметическое ',s/k);
readln
end.