s = input()
sep = s.split(' ')
t = int(sep[0])
a = int(sep[1])
b = int(sep[2])

import math
def lcm(x, y):
    return (x * y) // math.gcd(x, y)

def f(t, a):
    if t%a==0:
        return t//a
    else:
        return t//a+1

l = lcm(a, b)
ans = f(t,a) + f(t,b) - f(t,l)
print(ans)