program bai_tap;
uses crt;
var A:array[1..20] of integer;
n,i:byte;
t:integer;
begin
clrscr;
write('Nhap n: '); readln(n);
for i:=1 to n do
begin
write('Nhap so thu ',i,': '); readln(A[i]);
end;
if n=1 then t:=A[1] else t:=A[1]+A[n];
write('Tong phan tu dau va phan tu cuoi la: ',t);
readln;
end.