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# Дрон
# Ввод в одной строке: x y a b m d
x, y, a, b, m, d = map(int, input().split())

def distance_to_point(pos):
    return abs(pos)

def distance_between_points(pos1, pos2):
    return abs(pos1 - pos2)

def can_deliver_both(pos1, mass1, pos2, mass2):
    if mass1 + mass2 > m:
        return False
    
    route1 = distance_to_point(pos1) + distance_between_points(pos1, pos2) + distance_to_point(pos2)
    route2 = distance_to_point(pos2) + distance_between_points(pos2, pos1) + distance_to_point(pos1)
    
    min_distance = min(route1, route2)
    return min_distance <= d

def can_deliver_single(pos, mass):
    if mass > m:
        return False
    
    distance = 2 * distance_to_point(pos)
    return distance <= d

if can_deliver_both(x, a, y, b):
    print(1)
else:
    delivered_x = can_deliver_single(x, a)
    delivered_y = can_deliver_single(y, b)
    
    if delivered_x and delivered_y:
        print(2)
    elif not delivered_x and not delivered_y:
        print(-1)
    else:
        print(2)