import math

def lcm(a, b):
    return abs(a*b) // math.gcd(a, b)


# an+b=xn+y -> n=(y-b)/(a-x)
# -> cn+d
def merge(a, b, x, y):
    d1 = b
    d2 = y
    while d1 != d2:
        if d1 < d2:
            d1 += a * ((d2-d1-1) // a + 1)
        else:
            d2 += x * ((d1-d2-1) // x + 1)
    d = d1
    c = lcm(a, x)
    return c, d


lines = [x.strip() for x in open("input.txt")]
busses = ((int(x), -idx) for idx, x in enumerate(lines[1].split(',')) if x != 'x')

current = (1, 0)
for bus in busses:
    current = merge(*current, *bus)


print(current[1])