#!/bin/python3

import sys

def countArray(n, k, x):
    s=0
    for i in range(2,k+1):
            for j in range(n-3):
                for l in range(1,k+1):
                    if l!=x and l!=i:
                        s=s+1
    return s                   
                    
    # Return the number of ways to fill in the array.

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