def read_data():
    N = int(input())
    C, V = map(int, input().split())
    return N, C, V

def solve(N, C, V):
    dp = [float('inf')] * (1 + N)
    dpN = float('inf')
    dp[0] = 0
    dp[1] = C
    for k in range(1, N):
        cost = dp[k] + C
        for m in range(2 * k, N, k):
            cost += V
            if dp[m] > cost: dp[m] = cost
        dpN = min(dpN, cost + V - C)
    return min(dpN, dp[N])

N, C, V = read_data()
print(solve(N, C, V))