#D11959. Escape from the Hell
Escape from the Hell
Escape from the Hell
Example
Input
3 9 6 3 5 2 3 1 2 2 2
Output
2
inputFormat
Input
3 9 6 3 5 2 3 1 2 2 2
outputFormat
Output
2
样例
3 9
6 3
5 2
3 1
2
2
22
Example
Input
3 9 6 3 5 2 3 1 2 2 2
Output
2
Input
3 9 6 3 5 2 3 1 2 2 2
Output
2
3 9
6 3
5 2
3 1
2
2
22