题目描述

Once upon a time, high up on Mount Olympus, it came to pass that the gods held a competition to see who among them was the best at sorting lists of integers. Eris, the goddess of discord, finds this terribly boring and plans to add some mischief to the mix to make things more fun. She will sabotage the answers of Zeus so that his list of numbers is no longer sorted, which will no doubt be so embarrassing that he becomes furious and starts a minor war.

Eris must be careful not to be discovered while performing her sabotage, so she decides to only change a single digit in one of the numbers in Zeus’ answer. The resulting number may not have any leading zeros (unless it becomes equal to zero in which case a single zero digit is allowed). Eris can only replace a digit with another digit – adding or removing digits is not allowed

输入格式

输出格式

样例

3 
2020 2020 2020

2021 2020 2020

2 
1 9999999

impossible

4 
1 42 4711 9876

1 42 4711 3876

提示

By QLU_吹梦到西洲