////подключение билиотек и тд
.....
var
const
   n = 10;
c,f:text;
i,middle:integer;
a=array[1..10] of integer;
begin
assign (f, 'input.txt');
assign(c, 'output.txt');
reset(f);
for i:=1 to n do
	read(f,a[i]);
middle:=0;
for i:=1 to n do
	if (i mod 2=0)
    then
    middle:=middle+a[i];
    
 middle :=middle div 5;
 rewrite(c);
 write(c,middle);
close(f);
close(c);
end.