#!/usr/bin/env python3 import sys sys.setrecursionlimit(10000+3) h, a, d = map(int, input().split()) def e(i, memo={}): if i <= 0: return 0 else: if i not in memo: memo[i] = min(1 + e(i-a), 3/2 + e(i-d)) return memo[i] print(e(h))