Zadacha_490

def isAnswer(m, n, x, y):
    return (m//x) + (m//y) >= n


def find(n, x, y):
    l = 0
    r = n * x
    while l + 1 < r:
        m = (l + r)//2
        if isAnswer(m, n, x, y):
            print("time = ", m, "count = ", ((m//x) + (m//y)))
            r = m
        else:
            l = m
    return r


n, x, y = list(map(int, input().split()))

if x < y:
    x, y = y, x
        
print(find(n - 1, x, y) + y)