func main()
	const mod: int :: 1000000007
	var a: int :: cui@inputInt()
	var b: int :: cui@inputInt()
	var c: int :: cui@inputInt()
	var k: int :: cui@inputInt()
	var p: int :: math@modPow(2, k, mod - 1)
	do a :: math@modPow(a, p, mod)
	do b :: math@modPow(b, p, mod)
	do c :: math@modPow(c, p, mod)
	
	var ans: int :: a
	do ans :* b
	do ans :% mod
	do ans :* c
	do ans :% mod
	do cui@print("\{ans}\n")
end func