uses crt;
var a:array[1..20]of longint;
i,n,s:longint;
begin
clrscr;
write('Nhap so phan tu: ');readln(n);
for i:=1 to n do
begin
write('Nhap phan tu thu ',i,': ');readln(a[i]);
end;
s:=a[1]+a[n];
writeln('Tong cua phan tu dau va phan tu cuoi: ',s);
readln;
end.