package main

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

func main() {
	in := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(in, &n)

	prev := 0
	for i := 0; i < n; i++ {
		var t int
		fmt.Fscan(in, &t)
		if t-prev > 15 {
			fmt.Print(prev + 15)
			return
		}
		prev = t
	}

	if prev+15 < 90 {
		fmt.Print(prev + 15)
	} else {
		fmt.Print(90)
	}
}