package main

import "fmt"

func main() {
	var A, B float64
	fmt.Scan(&A, &B)

	if int(30*A+B/2)%360 == int(6*B)%360 {
		fmt.Println("0")
	} else {
		ans := 60 * (60*A - 11*B) / 11
		fmt.Println(int(ans))
	}
}