// No.1663 Maximum Remainder
package main

import "fmt"

func main() {
	var a, b, c, d, m int
	fmt.Scan(&a, &b, &c, &d, &m)

	var ans int
	for x := a; x <= b; x++ {
		for y := c; y <= d; y++ {
			ans = max(ans, (x+y)%m)
		}
	}
	fmt.Println(ans)
}