Buggy Sorting

Little boy Valera studies an algorithm of sorting an integer array. After studying the theory, he went on to the practical tasks. As a result, he wrote a program that sorts an array of n integers a₁, a₂, ..., a_n in the non-decreasing order. The pseudocode of the program, written by Valera, is given below. The input of the program gets number n and array a.

loop integer variable i from 1 to n - 1
    loop integer variable j from i to n - 1
        if (aj > aj + 1), then swap the values of elements aj and aj + 1

But Valera could have made a mistake, because he hasn't yet fully learned the sorting algorithm. If Valera made a mistake in his program, you need to give a counter-example that makes his program work improperly (that is, the example that makes the program sort the array not in the non-decreasing order). If such example for the given value of n doesn't exist, print -1.