CF56B Spoilt Permutation

Vasya collects coins: he has exactly one coin for every year from $ 1 $ to $ n $ . Naturally, Vasya keeps all the coins in his collection in the order in which they were released. Once Vasya's younger brother made a change — he took all the coins whose release year dated from $ l $ to $ r $ inclusively and put them in the reverse order. That is, he took a certain segment $ [l,r] $ and reversed it. At that the segment's endpoints did not coincide. For example, if $ n=8 $ , then initially Vasya's coins were kept in the order 1 2 3 4 5 6 7 8. If Vasya's younger brother chose the segment $ [2,6] $ , then after the reversal the coin order will change to 1 6 5 4 3 2 7 8. Vasya suspects that someone else could have spoilt the permutation after his brother. Help him to find that out. Check if the given permutation can be obtained from the permutation 1 2 ... $ n $ using exactly one segment reversal. If it is possible, find the segment itself.

The first line contains an integer $ n $ ( $ 1

If it is impossible to obtain the given permutation from the original one in exactly one action, print 0 0. Otherwise, print two numbers $ l $ $ r $ ( $ 1