uses crt;
var A : array [1 ..100] of integer;
i, N, d, j, k, S, S1 : integer;
begin
clrscr;
S := 0; S1 := 0; d := 0;
write('Nhap so N = '); readln(N);
write('Nhap day gom ', N ,' so : ');
for i := 1 to N do read(A[i]);
write('Vi tri : ');
for i := 1 to N do
begin
S1 := 0; S := 0;
for j := 1 to i do S := S + A[j];
for k := N downto i do S1 := S1 + A[k];
if S = S1 then
begin
write(i,' ');
d := d + 1;
end;
end;
if d = 0 then write(-1);
readln
end.