Uses crt;
Var A:Array[1..100000] of longint;
i, n, ch, tbc: longint;
Begin
Clrscr;
Write('Nhap n = '); readln(n);
For i:=1 to n do
Begin
Write('A[',i,']=');
Readln(A[i]);
End;
ch:=0;
tbc:=0;
For i:=1 to n do if a[i] mod 3 = 0 then
Begin
inc(ch);
tbc:=tbc+a[i];
End;
Writeln('Trung binh cong la: ',tbc/ch:4:2);
Readln
End.