# -*- encoding: utf-8 -*-
import sys

class Gato(object):

    def __init__(self, x, y):
        self.x = x
        self.y = y

    def addPasso(self):
        self.y += 1

    def isColidiu(self, x, y):
        if self.x == x and self.y== y:
            return True
        return False

    def __repr__(self):
        return 'X:{} Y:{}'.format(self.x, self.y)


class Carro(object):

    def __init__(self, x, y, v):
        self.x = x
        self.y = y
        self.v = v
        self.newCar = 0

    def addPasso(self):
        self.x += self.v

    def onMedium(self):
        if self.x > 6 and self.newCar == 0:
            self.newCar += 1
            return True
        return False

    def onEnd(self):
        if self.x >= 12:
            return True
        return False

    def __repr__(self):
        return 'X:{} Y:{} V:{}'.format(self.x, self.y, self.v)


line = sys.stdin.readline.split()
entradas = [int(l) for l in line]
cars = [Carro(0, y+1, v) for y, v in enumerate(entradas)]
cat = Gato(6,0)
colisao = 0

for x in xrange(0, 6):
    if colisao != 0:
        break
    else:
        cat.addPasso()
        for car in cars:
            car.addPasso()
            if cat.isColidiu(car.x, car.y):
                colisao = cat.y
                break
            else:
                if car.onMedium():
                    cars.append(Carro(0, car.y, car.v))
                if car.onEnd():
                    cars.remove(car)
print colisao