Title description: n smallest integer (n<1000000) are numbered from 1 to n, and a lookup integer m, please use the dichotomy to look up,
Enter
Input includes three lines, the first integer n, the second line contains n integers, separated by Spaces, the third behavior integer m,
O
If it can be found in the sequence of integers m, then the output number (if there are multiple number, returns the number of minimum), if not, the output None,