#! /usr/bin/env python

N, K, X = [int(token) for token in raw_input().strip().split()]

curr_val = 0 if X == 1 else 1
mod = 1000000007

def pow_mod(x, y):

    number = 1
    while y:
        if y & 1:
            number = number * x % mod
        y >>= 1
        x = x * x % mod
    return number

for n in range(3, N + 1):
    curr_val = pow_mod(K - 1, n - 2) - curr_val
    curr_val %= mod

print curr_val