package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	in := bufio.NewReader(os.Stdin)
	var n, m, s int64
	if _, err := fmt.Fscan(in, &n, &m, &s); err != nil {
		return
	}

	qn, rn := n/s, n%s
	var rows int64
	if rn == 0 {
		rows = n
	} else {
		rows = rn * (qn + 1)
	}

	qm, rm := m/s, m%s
	var cols int64
	if rm == 0 {
		cols = m
	} else {
		cols = rm * (qm + 1)
	}

	ans := rows * cols
	out := bufio.NewWriter(os.Stdout)
	fmt.Fprintln(out, ans)
	out.Flush()
}