#!/bin/python

import sys

def countArray(n, k, x):
    # Return the number of ways to fill in the array.
    return (n-3)*(k-1) + (k-2)

if __name__ == "__main__":
    n, k, x = raw_input().strip().split(' ')
    n, k, x = [int(n), int(k), int(x)]
    answer = countArray(n, k, x)
    print answer