from functools import reduce
from math import gcd


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


# f(n)=an+b and f(m)=xm+y
# Intersection of 2 sequences -> ck+d
def merge(a, b, x, y):
    while b != y:
        if b < y:
            b += a * ((y-b-1) // a + 1)
        else:
            y += x * ((b-y-1) // x + 1)
    return lcm(a, x), b


lines = [x.strip() for x in open("input.txt")]
# f(n) = [interval] * n + [offset]  -->  (interval, offset)
busses = ((int(x), -idx) for idx, x in enumerate(lines[1].split(',')) if x != 'x')
sequence = reduce(lambda fn, fm: merge(*fn, *fm), busses, (1, 0))
print(sequence[1])