uses crt;
var n,i,s,d:integer;
a:array[1..1000] of integer;
begin
clrscr;
write('n=');
readln(n); 
writeln ('nhap mang A:'); d:=0;
for i:=1 to n do
begin
 readln(a[i]);
 if a[i] mod 2=0 then begin d:=d+1; s:=s+a[i];end;
end;
writeln('trung binh cong: cac so chan:',s/d:0:5);
write('cac so o vi tri le:');
s:=0;
for i:=1 to n do
 if i mod 2=1 then write(a[i],' ') else if a[i] mod 2=0 then s:=s+a[i];
writeln;
writeln('tong cac so le o vi tri chan:',s);
readln;
end.

var n,s: real;
    i: integer;
    a: array[1..1000] of integer;
begin
    readln(n);
    s:=0;
    for i:=1 to n do begin
        read(a[i]);
        s:=s+a[i];
    end;
    writeln(s/n);
    for i:=1 to n do begin
        if (i mod 2 = 1) and (a[i] mod 2 = 0) then wriet(a[i],' /')
    end;
    writeln;
    for i:=1 to n do begin
        if (i mod 2 = 0) and (a[i] mod 2 = 1) then wriet(a[i],' /')
    end;
end.