Sum of Spiral Diagonals

You are given an odd integer n representing the dimensions of a square spiral. The spiral is created by starting with 1 at its center and moving to the right in a clockwise direction, filling the spiral in layers. Your task is to compute the sum of the numbers on both diagonals of this n × n spiral.

The pattern can be observed by noting that for each layer k (starting from k = 1 for the first outer layer), the step size is \(2k\). Each layer contributes 4 corner values, and the sum of these values (along with the center 1) gives the final result.

inputFormat

The input is a single integer n provided via standard input, which indicates the size of the spiral (an odd number).

outputFormat

The output is a single integer printed to standard output, representing the sum of the numbers on the diagonals of the spiral.

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