func main()
	var n: int :: cui@inputInt()
	var m: int :: cui@inputInt()
	var p: []float :: #[5]float
	do p[0] :: cui@inputFloat()
	for i(1, 4)
		do p[i] :: p[0] ^ (i + 1) $ float
	end for
	if(n > m)
		var tmp: int :: n
		do n :: m
		do m :: tmp
	end if
	
	var ans: float :: 0.0
	if(n = 1)
		if(m = 1)
			do ans :: p[0]
		else
			do ans :: 2.0 * p[1] + (m - 2) $ float * p[2]
		end if
	else
		do ans :: 4.0 * p[2] + (2 * n + 2 * m - 8) $ float * p[3] + ((n - 2) * (m - 2)) $ float * p[4]
	end if
	do cui@print("\{ans}\n")
end func