program Min;
uses crt;
var A:array[1..100] of integer;
n,i,dem,tong:integer;
tbc:real;
begin
clrscr;
tong:=0;
repeat
begin
write('Nhap n: ');
readln(n);
end;
until n<=100;
for i:=1 to n do
begin
write('Nhap so thu ',i,': ');
readln(A[i]);
end;
for i:=1 to n do
if i mod 2 <> 0 then
begin
inc(dem);
tong:=tong+A[i];
end;
tbc:=tong/dem;
writeln('So cac so le la: ',dem);
writeln('Tong cac so le la: ',tong);
writeln('Trung binh cong cac so le la: ',tbc:4:2);
readln
end.