import sys
import io, os
sys.setrecursionlimit(10**9)
input = io.BytesIO(os.read(0,os.fstat(0).st_size)).readline

h, a, d = map(int, input().split())

memo = {}
def rec(x):
    if x in memo:
        return memo[x]
    if x <= 0:
        return 0
    res = min(rec(x-a)+1, rec(x-d)+3/2)
    memo[x] = res
    return res
print(rec(h))