import sys
import math

def main():
    n = int(sys.stdin.readline())
    a = list(map(int, sys.stdin.readline().split()))
    m = min(a)
    sum_lcm = 0
    for num in a:
        g = math.gcd(m, num)
        sum_lcm += m * num // g
    print(sum_lcm - m)

if __name__ == "__main__":
    main()