// No.2691 Longest Infection Sequence
package main

import "fmt"

func main() {
	var a, b, o, w int
	fmt.Scan(&a, &b, &o, &w)

	ans := o + w
	if max(a, b) > 0 {
		ans += max(a, b)
	}
	fmt.Println(ans)
}