from functools import cache
import sys
sys.setrecursionlimit(10 ** 6)


@cache
def f(h) -> float:
    if h <= 0: return 0

    # 通常攻撃
    res = f(h - A) + 1
    # 必殺技
    res = min(res, f(h - D) + 3/2)

    return res


INF = 1 << 60
H, A, D = map(int, input().split())

ans = f(H)
print(ans)