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

ans = 10**18
if a >= d:
    ans = (h + a - 1) // a
else:
    cnt = 0
    while h >= 0:
        ans = min(ans, cnt + ((h + d - 1) // d) * 1.5)
        h -= a
        cnt += 1
print(ans)