H, A, D = map(int, input().split())
inf = 10 ** 18
M = 20005
dp = [inf] * M
dp[0] = 0
for i in range(1, M):
    if i - A >= 0:
        dp[i] = min(dp[i], dp[i - A] + 1)
    if i - D >= 0:
        dp[i] = min(dp[i], dp[i - D] + 1.5)
        
print(min(dp[H:]))