```go
package main

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

func main() {
	reader := bufio.NewReader(os.Stdin)
	var n, m, ta, tb, k int
	fmt.Fscan(reader, &n, &m, &ta, &tb, &k)

	a := make([]int64, n)
	for i := 0; i < n; i++ {
		fmt.Fscan(reader, &a[i])
	}

	b := make([]int64, m)
	for i := 0; i < m; i++ {
		fmt.Fscan(reader, &b[i])
	}

	if k >= n {
		fmt.Println(-1)
		return
	}

	var maxArrival int64 = 0
	for i := 0; i <= k; i++ {
		arrivalB := a[i] + int64(ta)
		idx := sort.Search(m, func(j int) bool { return b[j] >= arrivalB })

		if idx+(k-i) >= m {
			fmt.Println(-1)
			return
		}

		arrivalC := b[idx+(k-i)] + int64(tb)
		if arrivalC > maxArrival {
			maxArrival = arrivalC
		}
	}

	fmt.Println(maxArrival)
}
```