ICPC 2019 Qualifier: Test tour

Problem A. Repeating digit (easy) ≡

Input file:	input.txt		Time limit:	1 sec
Output file:	output.txt		Memory limit:	256 Mb

For given integers P and N you need to find all such values of x < 10^N, that N last digits of x^P are non-zero and equal.

Fortunately, there is not so many numbers showing this property. For example, for P = 2 and N = 2 there exist only 4 of them:

12, 38, 62, 88

Input file contains P and N.

Output the number of existing numbers X, then all these numbers in any order.

2 ≤ P ≤ 100

2 ≤ N ≤ 9

No.	Input file (`input.txt`)	Output file (`output.txt`)
1	`3 2`	`8 14 42 53 64 77 71 92 99`

Input file:	input.txt		Time limit:	2 sec
Output file:	output.txt		Memory limit:	4 Mb

Given the sequence of integers A₁, A₂, …, A_N, find a number A_s such that there exists exactly one A_m > A_s, and for all k ≠ m A_k ≤ A_s.

Input contains N followed by A₁ A₂… A_N.

Output should contain a single integer — A_s, or −1 if no such number exists.

1 ≤ N ≤ 1000000, 0 ≤ A_i ≤ 10⁹,

No.	Input file (`input.txt`)	Output file (`output.txt`)
1	`3 1 2 3`	`2`
2	`4 3 3 2 3`	`-1`