from math import gcd,
def rev(a, m):
    if a == 1:
        return 1
    return (1 - rev(m % a, a) * m) / a + m
def lcm(a,b):
    return (a * b) // gcd(a, b)
def solve_x(a1,m1,a2,m2):
    g = gcd(m1, m2)
    k = (a2 - a1) / g * rev(m1/g, m2/g) %  (m2/g)
    return a1 + k * m1
n = int(input())
a = [(int(input()), i + 2) for i in range(n)]
new_x = solve_x(*a[0],*a[1])
lc = lcm(a[0][1],a[1][1])
for i in range(2,len(a)):
    new_x = solve_x(new_x,lc,*a[i])
    lc = lcm(a[i][1],lc)
print(new_x)