A7920. Company Income Growth

Petya works as a PR manager for a successful Berland company BerSoft. He needs to prepare a presentation on the company income growth since $2001$ (the year of its founding) till now. Petya knows that in $2001$ the company income amounted to $a_{1}$ billion bourles, in $2002$ — to $a_{2}$ billion, ..., and in the current $(2000+n)$ -th year — $a_{n}$ billion bourles. On the base of the information Petya decided to show in his presentation the linear progress history which is in his opinion perfect. According to a graph Petya has already made, in the first year BerSoft company income must amount to $1$ billion bourles, in the second year — $2$ billion bourles etc., each following year the income increases by $1$ billion bourles. Unfortunately, the real numbers are different from the perfect ones. Among the numbers $a_{i}$ can even occur negative ones that are a sign of the company’s losses in some years. That is why Petya wants to ignore some data, in other words, cross some numbers $a_{i}$ from the sequence and leave only some subsequence that has perfect growth.

Thus Petya has to choose a sequence of years $y_{1}$ , $y_{2}$ , ..., $y_{k}$ ,so that in the year $y_{1}$ the company income amounted to $1$ billion bourles, in the year $y_{2}$ — $2$ billion bourles etc., in accordance with the perfect growth dynamics. Help him to choose the longest such sequence.

The first line contains an integer $n$ ( $1<=n<=100$ ). The next line contains $n$ integers $a_{i}$ ( $-100<=a_{i}<=100$ ). The number $a_{i}$ determines the income of BerSoft company in the $(2000+i)$ -th year. The numbers in the line are separated by spaces.

Output $k$ — the maximum possible length of a perfect sequence. In the next line output the sequence of years $y_{1}$ , $y_{2}$ , ..., $y_{k}$ . Separate the numbers by spaces. If the answer is not unique, output any. If no solution exist, output one number $0$ .