package main

import "fmt"

func main() {
	var n, first, now, ans int
	fmt.Scanf("%d", &n)

	first = 0;
	for i:=0; i<n; i++ {
		fmt.Scanf("%d", &now)
		if (now > (first + 15)) {
			ans = first + 15
			break
		} else {
			first = now
			ans = now + 15
		}
	}

	if ans < 15 {
		ans = 15
	}
	if ans > 90 {
		ans = 90
	}
	fmt.Printf("%d", ans)
}