t, s, d = map(int, input().split())
# h = d / s
# day, h = divmod(h, 24)
# ans = day * 12
# t = (t - 18) % 24
# if t < 12:
#     ans += min(12, t + h) - t
# if t + h >= 24:
#     ans += min(36, t + h) - 24
print(f'{d / s:.12f}')