import math
input_list = [int(num) for num in input().split()]
N = input_list[0]
X = input_list[1]
T = input_list[2]
ans = math.ceil(N / X) * T
print(ans)

a5511b04df687b28a921f7a46c948112c6756c2a
<mask token>

<mask token>
print(ans)

<mask token>
input_list = [int(num) for num in input().split()]
N = input_list[0]
X = input_list[1]
T = input_list[2]
ans = math.ceil(N / X) * T
print(ans)

import math
input_list = [int(num) for num in input().split()]
N = input_list[0]
X = input_list[1]
T = input_list[2]
ans = math.ceil(N / X) * T
print(ans)
