import math

n = int(input())
C, V = map(int, input().split())

min_cost = float('inf')

max_k = 20  # This can be adjusted based on problem constraints

def compute_product(m, k, t, n):
    product = 1
    for _ in range(t):
        product *= (m + 1)
        if product > n:
            return product
    for _ in range(k - t):
        product *= m
        if product > n:
            return product
    return product

for k in range(1, max_k + 1):
    if 2 ** k >= n:
        current_sum = 2 * k
        cost = V * current_sum + k * (C - V)
        if cost < min_cost:
            min_cost = cost
        continue
    
    left, right = 2, n
    best_m = 1
    while left <= right:
        mid = (left + right) // 2
        product = 1
        over = False
        for _ in range(k):
            product *= mid
            if product > n:
                over = True
                break
        if not over:
            best_m = mid
            left = mid + 1
        else:
            right = mid - 1
    
    m = best_m
    
    found = False
    for t in range(0, k + 1):
        product = compute_product(m, k, t, n)
        if product >= n:
            current_sum = m * (k - t) + (m + 1) * t
            cost = V * current_sum + k * (C - V)
            if cost < min_cost:
                min_cost = cost
            found = True
            break
    
    if not found:
        pass

print(min_cost)